M  A  R  S 
AND  ITS  CANALS 


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MARS   AND   ITS   CANALS 


MARS 

AND    ITS    CANALS 


BY 
PERCIVAL   LOWELL 


!T   PROFESSOR 
SOCIKTE 


HONORARY   MEMBER   OF  THE   SOCIF.DAD   ASTKONOMICA    DE   MEX- 
FRANCE,   1904,   FOR  RESEARCHES   ON   MARS;    ETC.,  ETC. 


ILLUSTRATED 


THE   MACMILLAN   COMPANY 

LONDON:  MACMILLAN  &  CO.,  LTD. 
1906 

All  rights  reserved 


COPYRIGHT,  1906, 
BY  THE  MACMILLAN  COMPANY. 


Set  up  and  electrotyped.      Published  December,  1906. 


XorfoooU  iSrtss 

J.  S.  Gushing  &  Co.  -  Berwick  &  Smith  Co. 
Norwood,  Mass.,  U.S.A. 


G.   V.    SCHIAPAKELLI 

THE   COLUMBUS  OF  A  NEW  PLANETARY  WORLD 

THIS  INVESTIGATION  UPON  IT 

IS   APPRECIATIVELY 

INSCRIBED 


PREFACE 

ELEVEN  years  have  elapsed  since  the  writer's  first 
work  on  Mars  was  published  in  which  were  recorded 
the  facts  gleaned  in  his  research  up  to  that  time 
and  in  which  was  set  forth  a  theory  of  their  explana- 
tion. Continued  work  in  the  interval  has  confirmed 
the  conclusions  there  stated ;  sometimes  in  quite 
unexpected  ways.  Five  times  during  that  period 
Mars  has  approached  the  earth  within  suitable  scan- 
ning distance  and  been  subjected  to  careful  and 
prolonged  scrutiny.  Familiarity  with  the  subject, 
improved  telescopic  means,  and  long-continued  train- 
ing have  all  combined  to  increased  efficiency  in  the 
procuring  of  data  and  to  results  which  have  been 
proportionate.  A  mass  of  new  material  has  thus 
been  collected,  —  some  of  it  along  old  lines,  some  of 
it  in  lines  that  are  themselves  new,  —  and  both  have 
led  to  the  same  outcome.  In  addition  to  thus  push- 
ing inquiry  into  advanced  portions  of  the  subject, 
study  has  been  spent  in  investigation  of  the  reality 
of  the  phenomena  upon  which  so  much  is  based,  and 
in  testing  every  theory  which  has  been  suggested  to 

vii 


viii  PREFACE 

account  for  them.  From  diplopia  to  optical  inter- 
ference, each  of  these  has  been  examined  and  found 
incompatible  with  the  observations.  The  phenomena 
are  all  they  have  been  stated  to  be,  and  more.  Each 
step  forward  in  observation  has  confirmed  the.  genu- 
ineness of  those  that  went  before. 

To  set  forth  science  in  a  popular,  that  is,  in  a 
generally  understandable,  form  is  as  obligatory  as  to 
present  it  in  a  more  technical  manner.  If  men  are 
to  benefit  by  it,  it  must  be  expressed  to  their  com- 
prehension. To  do  this  should  be  feasible  for  him 
who  is  master  of  his  subject  and  is  both  the  best 
test  of,  and  the  best  training  to,  that  post.  Espe- 
cially vital  is  it  that  the  exposition  should  be  done 
at  first  hand ;  for  to  describe  what  a  man  has  him- 
self discovered  comes  as  near  as  possible  to  making 
a  reader  the  co-discoverer  of  it.  Not  only  are  thus 
escaped  the  mistaken  glosses  of  second-hand  knowl- 
edge, but  an  aroma  of  actuality,  which  cannot  be 
filtered  through  another  mind  without  sensible  evap- 
oration, clings  to  the  account  of  the  pioneer.  Nor 
is  it  so  hard  to  make  any  well-grasped  matter  com- 
prehensible to  a  man  of  good  general  intelligence  as 
is  commonly  supposed.  The  whole  object  of  science 
is  to  synthesize,  and  so  simplify ;  and  did  we  but 
know  the  uttermost  of  a  subject  we  could  make  it 
singularly  clear.  Meanwhile  technical  phraseology, 


PBEFACE  ix 

useful  as  shorthand  to  the  cult,  becomes  meaningless 
jargon  to  the  uninitiate  and  is  paraded  most  by  the 
least  profound.  But  worse  still  for  their  employ 
symbols  tend  to  fictitious  understanding.  Formulae 
are  the  anaesthetics  of  thought,  not  its  stimulants ; 
and  to  make  any  one  think  is  far  better  worth  while 
than  cramming  him  with  ill-considered,  and  therefore 
indigestible,  learning. 

Even  to  the  technical  student,  a  popular  book,  if 
well  done,  may  yield  most  valuable  results.  For  noth- 
ing in  any  branch  of  science  is  so  little  known  as  its 
articulation,  —  how  the  skeleton  of  it  is  put  together, 
and  what  may  be  the  mode  of  attachment  of  its 
muscles. 


CONTENTS 


PART   I 

NATURAL  FEATURES 

CHAPTER 

I. 

ON  EXPLORATION          

3 

II. 

A  DEPARTURE-POINT     

12 

III. 

A  BIRD'S-EYE  VIEW  OF  PAST  MARTIAN  DISCOVERY 

20 

IV. 

THE  POLAR  CAPS          

32 

V. 

BEHAVIOR  OF  THE  POLAR  CAPS          .... 

41 

VI. 

MARTIAN  POLAR  EXPEDITIONS    

54 

VII. 

WHITE  SPOTS         

73 

VIII. 

CLIMATE  AND  WEATHER      

82 

IX. 

MOUNTAINS  AND  CLOUD       

96 

X. 

THE  BLUE-GREEN  AREAS     

108 

XL 

VEGETATION  

119 

XII. 

TERRAQUEOUSNESS  AND  TERRESTRIALITY 

128 

XIII. 

THE  REDDISH-OCHRE  TRACTS      

148 

XIV. 

SUMMARY       . 

159 

PART   II 

NON-NATURAL  FEATURES 

XV. 

THE  CANALS          

173 

XVI. 

184 

XVII. 

192 

I.   THE  DIPLOPIC  THEORY     . 

196 

II.   THE  INTERFERENCE  THEORY   .                 .        •    201 
III.   THE  ILLUSION  THEORY 202 


CONTENTS 


CHAPTER 

XVIII. 

THE  DOUBLE  CANALS        

PAGE 

204 

XIX. 

CANALS  IN  THE  DARK  REGIONS       .... 

243 

XX. 

OASES          

249 

XXL 

CARETS   ox   THE   BORDERS   OF   THE    GREAT   DIA- 

PHRAGM     

265 

XXII. 

THE  CANALS  PHOTOGRAPHED   

271 

PART   III 

THE   CANALS   IN  ACTION 

XXIII. 

CANALS:   KINEMATIC          

281 

XXIV. 

CANAL  DEVELOPMENT  INDIVIDUALLY  INSTANCED  . 

304 

XXV. 

HIBERNATION  OF  THE  CANALS          .        .        .        . 

313 

XXVI. 

ARCTIC  CANALS  AND  POLAR  RIFTS 

325 

XXVII. 

OASES  :   KINEMATIC    .        

330 

PART   IV 

EXPLANATION 

XXVIII. 

CONSTITUTION  OF  THE  CANALS  AND  OASES    . 

337 

XXIX. 

LIFE     

348 

XXX. 

EVIDENCE    

360 

XXXI. 

THE  HUSBANDING  OF  WATER  

366 

XXXII. 

INDEX 

CONCLUSION         .                

376 
385 

LIST   OF  ILLUSTRATIONS 

PLATES 


MARS'  HILL  Frontispiece 

PAGE 

8 

THE  SAN  FRANCISCO  PEAKS       ...... 

.       18 

MARTIAN  MAPS  BY: 

I.     BEER  AND  MAEDLER.     1840     .        . 

.      26 

II.     KAISER.     1864    . 

.      26 

III.     FLAMMARION  (RESUME).     1876 

.      27 

IV.     GREEN.     1877     

.      27 

V.      SCHIAPARELLI.      1877             

.      28 

VI.     SCHIAPARELLI.     1879         

.      28 

VII.     SCHIAPARELLI.     1881         .        .        . 

.      29 

VIII.     SCHIAPARELLI.     1884         .        .        .        .  '      . 

.      29 

IX.     LOWELL.     1894  

.      30 

X.     LOWELL.     1896  

.      30 

XI.     LOWELL.     1901  

.      31 

XII.     LOWELL.     1905  .        .        .        .        . 

31 

SOUTH  POLAR  CAP.     1905    

.      42 

NORTH  POLAR  CAP.     1905  

.      44 

MARE  ERYTHRAEUM,  MARTIAN  DATE,  DECEMBER  30 

.     120 

MARE  ERYTHRAEUM,  MARTIAN  DATE,  JANUARY  16 

.     122 

MARE  ERYTHRAEUM,  MARTIAN  DATE,  FEBRUARY  1 

.     124 

MARE  ERYTHRAEUM,  MARTIAN  DATE,  FEBRUARY  21 

.     120 

MARS,  ON  MERCATOR'S  PROJECTION    

.    384 

CUTS  APPEARING  IN   TEXT 

SOUTH  POLAR  CAP  IN  WINTER    

.      56 

HELLAS  IN  WINTER       

.      59 

xiii 

xiv  LIST   OF  ILLUSTRATIONS 

PAGE 

WHITE  SOUTH  OF  NECTAR  AND  SOLIS  LACUS  ....  59 

NORTHERN  CAP  HOODED  WITH  VAPOR 64 

NORTHERN  CAP  UNMASKED 65 

DEPOSITION  OF  FROST 70 

FIRST  NORTHERN  SNOW 72 

WHITE  IN  ELYSIUM .        .        .75 

WHITE  IN  THE  PONS  HECTORIS .78 

PROJECTION  ON  TERMINATOR       .        ...        .        .        .  101 

LINES    IN    DARK    AREA 117 

MAP  OF  NORTH  AMERICA  AT  THE  CLOSE  OF  ARCHAEAN  TIME  132 
NORTH  AMERICA  AT  OPENING  OF  UPPER  SILURIAN  PERIOD    .  134 
MAP  OF  NORTH  AMERICA  AFTER   THE  APPALACHIAN    REVO- 
LUTION                 .        .        .        .        .  135 

NORTH  AMERICA  IN  THE  CRETACEOUS  PERIOD         .        .        .  136 
NORTH    AMERICA,    SHOWING    THE   PARTS    UNDER   WATER    IN 

THE  TERTIARY  ERA 137 

EARTH'S  DESERT  AREAS,  WESTERN  HEMISPHERE    .        .        .  156 

EARTH'S  DESERT  AREAS,  EASTERN  HEMISPHERE     .        .        .  157 

SHOWING  THE  EUMENIDES-ORCUS 183 

MARTIAN  DOUBLES 206 

MARTIAN  DOUBLES 207 

MOUTHS  OF  EUPHRATES  AND  PHISON.    JUNE,  1903          .        .  219 

PECULIAR  DEVELOPMENT  OF  THE  GANGES         ....  228 

D.IIHOUN,  THE  NARROWEST  DOUBLE 229 

THE   SABAEUS  SINUS,   EMBOUCHURE   FOR  THE    DOUBLE   HID- 

DEKEL    AND    GlHON 232 

THE  PROPOXTIS,  1905 .247 

FONS  IMMORTALIS,  JUNE  19 254 

UTOPIA  REGIO.     1903 256 

ASCRAEUS  Lucus  AND  GiGAs.     MARCH  2,  1903        .        .        .  258 
PECULIAR   ASSOCIATION  OF  THE  Luci  ISMENII  WITH  DOUBLE 

CANALS 260 

Lucus  ISMENIUS.     MARCH,  1903 262 

SHOWING  SEASONAL  CHANGE.     I 285 


LIST   OF   ILLUSTRATIONS  xv 

PAGE 

SHOWING  SEASONAL  CHANGE.    II 285 

MEAN  CANAL  CARTOUCHES 298 

SHOWING  DEVELOPMENT  OF  THE  BRONTES  : 

I.    FEBRUARY  25 .        .        .  306 

II.    MARCH  30 307 

III.  APRIL  3 307 

IV.  MAY  4 »        .        .        .        .308 

V.     MAY  7 .        .        .        .308 

VI.    JULY  18         .        .        . 309 

CARTOUCHES  OF  THE  BRONTES   .        .        ,        .        .        .        .  311 

AMENTHES  ALONE  IN  FEBRUARY 319 

AMENTHES  FEEBLER  AND  STILL  ALONE  IN  MARCH  .        .        .  319 
APPEARANCE  OF  THOTH  WITH  TRITON  AND  CURVED  NEPEN- 
THES.    AMENTUES  VANISHED,  APRIL  20          ...  320 
ADVENT  OF  THE  Lucus  MOERIS.     MAY  29       ....  321 
AMENTHES  WITH  THOTH-NEPENTHES.    JULY     ....  322 
CARTOUCHES   OF    AMENTHES,   THOTH,  AND   THEIR    COMBINA- 
TION       323 

PHENOLOGY  CURVES  —  EARTH 342 

PHENOLOGY  CURVES  —  MARS 343 


PAKT   I 
NATURAL   FEATURES 


MARS  AND   ITS   CANALS 

CHAPTER   I 

ON   EXPLORATION 

TT^ROM  time  immemorial  travel  and  discovery 
-*-  have  called  with  strange  insistence  to  him  who, 
wondering  on  the  world,  felt  adventure  in  his  veins. 
The  leaving  familiar  sights  and  faces  to  push  forth  into 
the  unknown  has  with  magnetic  force  drawn  the  bold 
to  great  endeavor  and  fired  the  thought  of  those  who 
stayed  at  home.  Spur  to  enterprise  since  man  first 
was,  this  spirit  has  urged  him  over  the  habitable  globe. 
Linked  in  part  to  mere  matter  of  support  it  led  the 
more  daring  of  the  Aryans  to  quit  the  shade  of  their 
beech  trees,  reposeful  as  that  umbrage  may  have  been, 
and  wander  into  Central  Asia,  so  to  perplex  philolo- 
gists into  believing  them  to  have  originated  there; 
it  lured  Columbus  across  the  waste  of  waters  and 
caused  his  son  to  have  carved  upon  his  tomb  that 
ringing  couplet  of  which  the  simple  grandeur  still 
stirs  the  blood :  — 

A  CASTILLA  Y  A  LEON 

XUEVO    MOSTDO    BIO    COLOX  ; 

(To  Castile  and  Leon  beyond  the  wave 
Another  world  Columbus  gave;) 


4  MARS  AND   ITS   CANALS  CHAP,  i 

it  drove  the  early  voyagers  into  the  heart  of  the  vast 
wilderness,  there  to  endure  all  hardship  so  that  they 
might  come  where  their  kind  had  never  stood  before; 
and  now  it  points  man  to  the  pole. 

Something  of  the  selfsame  spirit  finds  a  farther 
field  today  outside  the  confines  of  our  traversable 
earth.  Science  which  has  caused  the  world  to  shrink 
and  dwindle  has  been  no  less  busy  bringing  near  what 
in  the  past  seemed  inaccessibly  remote.  Beyond  our 
earth  man's  penetration  has  found  it  possible  to  pierce, 
and  in  its  widening  circle  of  research  has  latterly  been 
made  aware  of  another  world  of  strange  enticement 
across  the  depths  of  space.  Planetary  distances,  not 
mundane  ones,  are  here  concerned,  and  the  globe  to  be 
explored,  though  akin  to,  is  yet  very  different  from, 
our  own.  This  other  world  is  the  planet  Mars. 
Sundered  from  us  by  the  ocean  of  ether,  a  fellow- 
member  of  our  own  community  of  matter  there  makes 
its  circuit  of  the  sun  upon  whose  face  features  show 
which  stamp  it  as  cognate  to  that  on  which  we  live. 
In  spite  of  the  millions  of  miles  of  intervening  mat- 
terless  void,  upon  it  markings  can  be  made  out  that 
distantly  resemble  our  earth's  topography  and  grow 
increasingly  suggestive  as  vision  shapes  them  better; 
and  yet  among  the  seemingly  familiar  reveal  aspects 
which  are  completely  strange.  But  more  than  this : 
over  the  face  of  it  sweep  changes  that  show  it  to  be 


CHAP,  i  ON  EXPLORATION"  5 

not  a  dead  but  a  living  world,  like  ours  in  this,  and 
luring  curiosity  by  details  unknown  here  to  further 
exploration  of  its  unfamiliar  ground. 

To  observe  Mars  is  to  embark  upon  this  enterprise; 
not  in  body  but  in  mind.  Though  parted  by  a  gulf 
more  impassable  than  any  sea,  the  telescope  lets  us 
traverse  what  otherwise  had  been  barred  and  lands  us 
at  last  above  the  shores  we  went  forth  to  seek.  Real 
the  journey  is,  though  incorporeal  in  kind.  Since  the 
seeing  strange  sights  is  the  essence  of  all  far  wander- 
ings, it  is  as  truly  travel  so  the  eye  arrive  as  if  the  body 
kept  it  company.  Indeed,  sight  is  our  only  far  viatic 
sense.  Touch  and  taste  both  hang  on  contact,  smell 
stands  indebted  to  the  near  and  even  hearing  waits  on 
ponderable  matter  where  sound  soon  dissipates  away; 
only  sight  soars  untrammeled  of  the  grosser  adjunct  of 
the  flesh  to  penetrate  what  were  otherwise  unfathom- 
able space. 

What  the  voyager  thus  finds  himself  envisaging- 
shares  by  that  very  fact  in  the  expansion  of  the  sense 
that  brought  him  there.  No  longer  tied  by  means  of 
transport  to  seas  his  sails  may  compass  or  lands  his 
feet  may  tread,  the  traveler  reaches  a  goal  removed  in 
kind  from  his  own  habitat.  He  proves  to  have  ad- 
ventured, not  into  unknown  parts  of  a  known  world, 
but  into  one  new  to  him  in  its  entirety.  In  extent 
alone  he  surveys  what  dwarfs  the  explorer's  conquests 


6  MARS  AND  ITS   CANALS  CHAP,  i 

on  Earth.  But  size  is  the  least  of  the  surprises  there 
in  store  for  him.  What  confronts  his  gaze  finds  com- 
monly no  counterpart  on  Earth.  His  previous  knowl- 
edge stands  him  in  scant  stead.  For  he  faces  what  is 
so  removed  from  every  day  experience  that  analogy  no 
longer  offers  itself  with  safety  as  a  guide.  He  must 
build  up  new  conceptions  from  fresh  data  and  slowly 
proceed  to  deduce  the  meaning  they  may  contain. 
Science  alone  can  help  him  to  interpretation  of  what 
he  finds,  and  above  all  must  he  wean  himself  from 
human  prejudice  and  earthbound  limitation.  For  he 
deals  here  with  ultramundane  things.  With  just 

""enough  of  cosmogony  in  common  to  make  decipher- 
ment not  despairable  this  world  is  yet  so  different 
from  the  one  he  personally  knows  as  to  whet  curiosity 
at  every  turn.  He  is  permitted  to  perceive  what 

^piques  inquiry  and  by  patient  adding  of  point  to  point 
promises  at  last  a  rational  result. 

Like  mundane  exploration,  it  is  arduous  too;  ad 
astra  per  aspera  is  here  literally  true.  For  it  is  a 
journey  not  devoid  of  hardship  and  discomfort  by  the 
way.  Its  starting-point  preludes  as  much.  To  get 
conditions  proper  for  his  work  the  explorer  must  forego 
the  haunts  of  men  and  even  those  terrestrial  spots  found 
by  them  most  habitable.  Astronomy  now  demands 
bodily  abstraction  of  its  devotee.  Its  deities  are  gods 
that  veil  themselves  amid  man-crowded  marts  and 


CHAP,  i  ON  EXPLORATION  7 

impose  withdrawal  and  seclusion  for  the  prosecution  of 
their  cult  as  much  as  any  worshiped  for  other  reason 
in  more  primeval  times.  To  see  into  the  beyond  re- 
quires purity;  in  the  medium  now  as  formerly  in  the 
man.  As  little  air  as  may  be  and  that  only  of  the 
best  is  obligatory  to  his  enterprise,  and  the  securing  it 
makes  him  perforce  a  hermit  from  his  kind.  He  must 
abandon  cities  and  forego  plains.  Only  in  places  raised 
above  and  aloof  from  men  can  he  profitably  pursue 
his  search,  places  where  nature  never  meant  him  to 
dwell  and  admonishes  him  of  the  fact  by  sundry 
hints  of  a  more  or  less  distressing  character.  To 
stand  a  mile  and  a  half  nearer  the  stars  is  not  to 
stand  immune. 

Thus  it  comes  about  that  today  besides  its  temples 
erected  in  cities,  monasteries  in  the  wilds  are  being 
dedicated  to  astronomy  as  in  the  past  to  faith ;  mon- 
asteries made  to  commune  with  its  spirit,  as  temples 
are  to  communicate  the  letter  of  its  law.  Pioneers  in 
such  profession,  those  already  in  existence  are  but  the 
precursors  of  many  yet  to  come  as  science  shall  more 
and  more  recognize  their  need.  Advance  in  knowl- 
edge demands  what  they  alone  can  give.  Primitive, 
too,  they  must  be  as  befits  the  still  austere  sincerity 
of  a  cult,  in  which  the  simplest  structures  are  found 
to  be  the  best. 

Still  the  very  wildness  of  the  life  their  devotee  is 


8  MAES   AND   ITS   CANALS  CHAP,  i 

forced  to  lead  has  in  it  a  certain  fittingness  for  his  post 
in  its  primeval  detachment  from  the  too  earthbound, 
in  concept  as  in  circumstance.  Withdrawn  from  con- 
tact with  his  kind,  he  is  by  that  much  raised  above 
human  prejudice  and  limitation.  To  sally  forth  into 
the  untrod  wilderness  in  the  cold  and  dark  of  a 
winter's  small  hours  of  the  morning,  with  the  snow  feet 
deep  upon  the  ground  and  the  frosty  stars  for  mute 
companionship,  is  almost  to  forget  one's  self  a  man 
for  the  solemn  awe  of  one's  surroundings.  Fitting 
portal  to  communion  with  another  world,  it  is  through 
such  avenue  one  enters  on  his  quest  where  the  com- 
mon and  familiar  no  longer  jostle  the  unknown  and 
the  strange.  Nor  is  the  stillness  of  the  stars  invaded 
when  some  long  unearthly  howl,  like  the  wail  of  a  lost 
soul,  breaks  the  slumber  of  the  mesa  forest,  marking 
the  prowling  presence  of  a  stray  coyote.  Gone  as  it 
came,  it  dies  in  the  distance  on  the  air  that  gave  it 
birth;  and  the  gloom  of  the  pines  swallows  up  one's 
vain  peering  after  something  palpable,  their  tops  alone 
decipherable  in  dark  silhouette  against  the  sky.  From 
amid  surroundings  that  for  their  height  and  their 
intenancy  fringe  the  absolute  silence  of  space  the 
observer  must  set  forth  who  purposes  to  cross  it  to 
another  planetary  world. 

But  the  isolation  of  his  journey  is  not  always  so  for- 
bidding.    His  coming  back  is  no  less  girt  with  grandeur 


CHAP.J  ON  EXPLORATION  9 

of  a  different  though  equally  detached  a  kind.  Even 
before  the  stars  begin  to  dim  in  warning  to  him  to  re- 
turn, a  faint  suffusion  as  of  half-suspected  light  creeps 
into  the  border  of  the  eastern  sky.  Against  it,  along 
the  far  pine-clad  horizon,  mesa  after  mesa  in  shaggy 
lines  of  sentineling  earth,  stands  forth  dark  marshaled 
in  the  gloom,  informed  with  prescience  of  what  is  soon 
to  come.  Imperceptibly  the  pallor  grows,  blanching 
the  face  of  night  and  one  by  one  extinguishing  the  stars. 
Slowly  then  it  takes  on  color,  tingeing  ever  so  faintly 
to  a  flush  that  swells  and  deepens  as  the  minutes  pass. 
One  had  said  the  sky  lay  dreaming  of  the  sun  in  pale 
imagery  at  first  that  gathers  force  and  feeling  till  the 
dreamer  turns  thus  rosy  red  in  slumbering  supposition 
of  reality.  Then  the  blush  dies  out.  The  crimson  fades 
to  pink,  the  pink  to  ashes.  The  stars  have  disappeared 
and  yet  it  is  not  day.  It  is  the  supreme  moment  of  the 
dawn,  the  hush  with  which  the  Earth  awaits  its  full 
awakening.  For  now  again  the  color  gathers  in  the  east, 
not  with  the  impalpable  suffusion  it  had  before  but 
nearer  and  more  vivid.  No  longer  reflectively  remote, 
rays  imminent  of  the  sun  strike  the  upper  air,  the  most 
adventurously  refrangible  turning  the  underside  of  a 
few  stray  clouds  into  flame-hued  bars  of  glowing  metal. 
They  burn  thus  in  the  silent  east  first  red,  then  orange, 
and  then  gold,  each  spectral  tint  in  prismatic  reve- 
lation coming  to  join  the  next  till  in  a  sudden 


10  MARS  AND  ITS  CANALS  CHAP,  i 

blinding  burst  of  splendor  the  solar  disk  tops  the 
horizon's  rim. 

Not  less  impressive  is  the  journey  when  the  afternoon 
watch  has  replaced  the  morning  vigil  by  the  drawing  of 
the  planet  nearer  to  the  sun.  Lost  in  the  brilliance  of 
the  dazzling  sky,  the  planet  lies  hid  from  the  senses' 
search.  The  quest  were  hopeless  did  not  the  mind  guide 
the  telescope  to  its  goal.  To  theory  alone  is  it  visible 
still,  and  so  to  its  predicted  place  the  observer  sets  his 
circles,  and  punctual  to  the  prophecy  the  planet  swings 
into  the  field  of  view.  One  must  be  dulled  by  long 
routine  to  such  mastery  of  mind  not  to  have  the  act 
itself  clothe  with  a  sense  of  charmed  withdrawal  the 
object  of  his  quest. 

So  much  and  more  there  are  of  traveler's  glimpses 
by  the  way,  compensation  that  offsets  the  frequent  dis- 
comfort, and  even  balking  of  his  purpose  by  inoppor- 
tune cloud.  For  the  best  of  places  is  not  perfect,  and  a 
storm  will  sometimes  rob  him  of  a  region  he  wished  to 
see.  He  must  learn  to  wait  upon  his  opportunities  and 
then  no  less  to  wait  for  mankind's  acceptance  of  his 
results;  for  in  common  with  most  explorers  he  will 
encounter  on  his  return  that  final  penalty  of  penetra- 
tion, the  certainty  at  first  of  being  disbelieved. 

In  such  respect  he  will  be  even  worse  off  than  were  the 
other  world  discoverers  of  the  fifteenth  and  sixteenth 
centuries.  For  they  at  least  could  offer  material  proof 


CHAP,  i  OK  EXPLOKATION  11 

of  things  that  they  had  seen.  Dumb  Indians  and  gold 
spoke  more  convincingly  than  the  lips  of  the  great  navi- 
gators. To  astronomy,  too,  that  other  world  was  due. 
Without  a  knowledge  of  the  earth's  shape  and  size  got 
from  Francisco  of  Pisa,  Columbus  had  never  adventured 
himself  upon  the  deep.  But  more  than  this,  an  as- 
tronomer it  was,  in  the  person  of  Americus  Vespucius, 
who  first  discovered  the  new  world,  by  recognizing  it 
as  such ;  Columbus  never  dreaming  he  had  lighted  upon 
a  world  that  was  new.  Nor  does  it  impair  one  jot  or 
tittle  of  his  glory  that  he  knew  it  not.  Nothing  can 
deprive  him  of  the  imperishable  fame  of  launching 
forth  into  the  void  in  hope  of  a  beyond,  though  he 
found  not  what  he  sought  but  something  stranger  still. 
So,  curiously,  has  it  been  with  the  trans-etherian. 
To  Schiaparelli  the  republic  of  science  owes  a  new  and 
vast  domain.  His  genius  first  detected  those  strange 
new  markings  on  the  Martian  disk  which  have  proved 
the  portal  to  all  that  has  since  been  seen,  and  his  courage 
in  the  face  of  universal  condemnation  led  to  explora- 
tion of  them.  He  made  there  voyage  after  voyage, 
much  as  Columbus  did  on  Earth,  with  even  less  of  rec- 
ognition from  home.  As  with  Columbus,  too,  the  full 
import  of  his  great  discovery  lay  hid  even  to  him  and 
only  by  discoveries  since  is  gradually  resulting  in  rec- 
ognition of  another  sentient  world. 


CHAPTER    II 

A   DEPARTURE-POINT 

A  S  the  character  of  the  travel  is  distinctive,  so  the 
outcome  of  the  voyage  is  unique.  If  he  choose  his 
departure-point  aright,  the  observer  will  be  vouchsafed 
an  experience  without  parallel  on  Earth.  To  select 
this  setting-out  station  is  the  first  step  in  the  journey 
upon  which  everything  depends.  For  it  is  essential 
to  visual  arrival  that  a  departure-point  be  taken  where 
definition  is  at  its  best.  Now,  so  far  as  our  present 
knowledge  goes,  the  conditions  most  conducive  to 
good  seeing  turn  out  to  lie  in  one  or  other  of  the  two 
great  desert  belts  that  girdle  the  globe.  Many  of  us 
are  unaware  of  the  existence  of  such  belts  and  yet  they 
are  among  the  most  striking  features  of  physical  geog- 
raphy. Could  we  get  off  our  globe  and  view  it  from 
without  we  should  mark  two  sash-like  bands  of  coun- 
try, to  the  poleward  side  of  either  tropic,  where  the  sur- 
face itself  lay  patently  exposed.  Unclothed  of  verdure 
themselves  they  would  stand  forth  doubly  clear  by  con- 
trast. For  elsewhere  cloud  would  hide  to  a  greater  or 
less  extent  the  actual  configuration  of  the  Earth's 
topography  to  an  observer  scanning  it  from  space. 
12 


CHAP,  ii  A    DEPARTUEE-POINT  13 

One  of  these  sash-like  belts  of  desert  runs  through 
southern  California,  Arizona,  New  Mexico,  the  Sahara, 
Arabia  Petrsea  and  the  Desert  of  Gobi;  the  other 
traverses  Peru,  the  South  African  veldt,  and  Western 
Australia.  They  are  desert  because  in  them  rain  is 
rare;  and  even  clouds  seldom  form.  In  a  twofold 
way  they  conduce  to  astronomic  ends.  Absence  of 
rain  makes  primarily  for  clear  skies  and  secondarily 
for  steady  air;  and  the  one  of  these  conditions  is  no 
less  vital  to  sight  than  the  other.  Water  vapor  is  a 
great  upsetter  of  atmospheric  equilibrium  and  com- 
motion in  the  air  the  spoiler  of  definition.  Thus  from 
the  cloudlessness  of  their  skies  man  finds  in  them  most 
chance  of  uninterrupted  communion  with  the  stars, 
while  by  suitably  choosing  his  spot  he  here  obtains  as 
well  that  prime  desideratum  for  planetary  work,  as 
near  a  heavenly  equanimity  in  the  air  currents  over 
his  head  as  is  practically  possible. 

From  the  fact  that  these  regions  are  desert  they  are 
less  frequented  of  man,  and  the  observer  is  thus  perforce 
isolated  by  the  nature  of  the  case,  the  regions  best 
adapted  to  mankind  being  the  least  suited  to  astronomic 
observations.  In  addition  to  what  nature  has  thus 
done  in  the  matter,  humanity  has  further  differentiated 
the  two  classes  of  sights  by  processes  of  its  own  contriv- 
ing. Not  only  is  civilized  man  actively  engaged  in  de- 
facing such  part  of  the  Earth's  surface  as  he  comes  in 


14  MARS  AND  ITS   CANALS  CHAP,  n 

contact  with,  he  is  equally  busy  blotting  out  his  sky. 
In  the  latter  uncommendable  pursuit  he  has  in  the  last 
quarter  of  a  century  made  surprising  progress.  With  a 
success  only  too  undesirable  his  habitat  has  gradually 
become  canopied  by  a  welkin  of  his  own  fashioning, 
which  has  rendered  it  largely  unfit  for  the  more  delicate 
kinds  of  astronomic  work.  Smoke  from  multiplying 
factories  by  rising  into  the  air  and  forming  the  nucleus 
about  which  cloud  collects  has  joined  with  electric 
lighting  to  help  put  out  the  stars.  These  concomitants 
of  advancing  civilization  have  succeeded  above  the 
dreams  of  the  most  earth-centred  in  shutting  off  sight 
of  the  beyond  so  that  today  few  city-bred  children 
have  any  conception  of  the  glories  of  the  heavens 
which  made  of  the  Chaldean  shepherds  astronomers  in 
spite  o'f  themselves. 

.  The  old  world  and  the  new  are  alike  affected  by 
such  obliteration.  Long  ago  London  took  the  lead 
with  fogs  proverbial  wholly  due  to  smoke,  fine  parti- 
cles^ solid  matter  in  suspension  making  these  points 
of  condensation  about  which  water  vapor  gathers  to 
form  cloud.  With  the  increase  of  smoke-emitting 
chimneys  over  the  world  other  centres  of  population 
have  followed  suit  till  today  Europe  and  eastern  North 
America  vie  with  each  other  as  to  which  sky  shall  be 
the  most  obliterate.  Even  when  the  obscuration  is  not 
patent  to  the  layman  it  is  evident  to  the  meteorologist 


CHAP,  ii  A   DEPAKTU  RE-POINT  15 

or  astronomer.  By  a  certain  dimming  of  the  blue, 
smoke  or  dust  reveals  its  presence  high  up  aloft  as 
telltalely  as  if  the  thing  itself  were  visible.  Some  time 
since  the  writer  had  occasion  to  traverse  Germany  in 
summer  from  Gottingen  to  Cologne  and  in  so  doing  was 
impressed  by  a  cloudiness  of  the  sky  he  felt  sure  had  not 
existed  when  he  knew  it  as  a  boy.  For  the  change 
was  too  startling  and  extensive  to  be  wholly  laid  to  the 
score  of  the  brighter  remembrances  of  youth.  On 
reaching  Cologne  he  mentioned  his  suspicion  to  Klein, 
only  to  find  his  own  inference  corroborated;  observa- 
tions made  twenty  years  ago  being  impracticable  today. 
Two  years  later  in  Milan  Celoria  told  the  same  story, 
the  study  of  Mars  having  ceased  to  be  possible  there  for 
like  cause.  Factory  smoke  and  electric  lights  had  com- 
bined to  veil  the  planet  at  about  the  time  Schiaparelli 
gave  up  his  observations  because  of  failing  sight.  With 
a  certain  poetic  fitness  the  sky  had  itself  been  blotted 
just  at  the  time  the  master's  eye  had  dimmed. 

America  is  not  behind  in  this  race  for  sky  extinction. 
In  the  neighborhood  of  its  great  cities  and  spreading  into 
the  country  round  about  the  heavens  have  ceased  to  be 
favorable  to  research.  Not  till  we  pass  beyond  the 
Missouri  do  the  stars  shine  out  as  they  shone  before  the 
white  man  came. 

Few  astronomers  even  fully  appreciate  how  much  this 
means,  so  used  does  man  get  to  slowly  changing  condi- 


16  MARS  AND   ITS   CANALS  CHAP.  H 

tions.  It  amounts,  indeed,  between  Washington  and 
Arizona  to  a  whole  magnitude  in  the  stars  which  may 
be  seen.  At  the  Naval  Observatory  of  the  former 
sixty-four  stars  were  mapped  in  a  region  where  with  a 
slightly  smaller  glass  one  hundred  and  seventy-two  were 
charted  at  Flagstaff. 

Besides  their  immediate  use  as  observing  stations 
these  desert  belts  possess  mediate  interest  on  their  own 
account  in  a  branch  of  the  very  study  their  cloudless- 
ness  helps  to  promote,  the  branch  here  considered,  the 
study  of  the  planet  Mars.  They  help  explain  what  they 
permit  to  be  visible.  For  in  the  physical  history  of  the 
Earth's  development  they  are  among  the  latest  phe- 
nomena and  mark  the  beginning  of  that  stage  of  world 
evolution  into  which  Mars  is  already  well  advanced. 
They  are  symptomatic  of  the  passing  of  a  terraqueous 
globe  into  a  purely  terrestrial  one.  Desertism,  the  state 
into  which  every  planetary  body  must  eventually  come 
and  for  which,  therefore,  it  becomes  necessary  to  coin  a 
word,  has  there  made  its  first  appearance  upon  the 
Earth.  Standing  as  it  does  for  the  approach  of  age 
in  planetary  existence,  it  may  be  likened  to  the  first 
gray  hairs  in  man.  Or  better  still  it  corresponds  to 
early  autumnal  frost  in  the  passage  of  the  seasons. 
For  the  beginning  to  age  in  a  planet  means  not  decrep- 
itude in  its  inhabitants  but  the  very  maturing  of  this 
its  fruit.  Evolution  of  mind  in  its  denizens  continues 


CHAP,  ii  A  DEPAKTUKE-POINT  17 

long  after  desolation  in  their  habitat  has  set  in. 
Indeed,  advance  in  brain-power  seriously  develops 
only  when  material  conditions  cease  to  be  bodily  pro- 
pitious and  the  loss  of  corporeal  facilities  renders  its 
acquisition  necessary  to  life. 

The  resemblance,  distant  but  distinctive,  of  the  cli- 
matic conditions  necessary  on  earth  for  the  best  scan- 
ning of  Mars  with  those  which  prove  to  be  actually  exist- 
ent on  that  other  world  has  a  bearing  on  the  subject 
worth  considerable  attention.  It  helps  directly  to  an 
understanding  and  interpretation  of  the  Martian  state 
of  things.  Though  partial  only,  the  features  and  traits 
of  our  arid  zones  are  sufficiently  like  what  prevails  on 
Mars  to  make  them  in  some  sort  exponent  of  physical 
conditions  and  action  there.  Much  that  is  hard  of 
appreciation  in  a  low,  humid  land  shows  itself  an  every- 
day possibility  in  a  high  and  dry  one.  The  terrible 
necessity  of  water  to  all  forms  of  life,  animal  or  vegetal, 
so  that  in  the  simple  thought  of  the  aborigines  rain  is 
the  only  god  worth  great  propitiation  upon  the  due 
observance  of  which  everything  depends,  brings  to  one 
a  deeper  realization  of  what  is  really  vital  and  what  but 
accessory  at  best.  One  begins  to  conceive  what  must 
be  the  controlling  principle  of  a  world  where  water  is 
only  with  difficulty  to  be  had,  and  rain  unknown.  . 

But  in  addition  to  the  fundamental  importance  of 
water,  the  relative  irrelevancy  of  some  other  conditions 


18  MARS   AND  ITS   CANALS  CHAP,  n 

usually  deemed  indispensable  to  organic  existence 
there  find  illustration  too.  On  the  high  plateau  of 
northern  Arizona  and  on  the  still  higher  volcanic  cones 
that  rise  from  them  as  a  base  into  now  disintegrating 
peaks,  the  thin  cold  air  proves  no  bar  to  life.  To  the 
fauna  there  air  is  a  very  secondary  consideration  to 
water,  and  because  the  latter  is  scarce'  in  the  lowlands 
and  more  abundant  higher  up,  animals  ascend  after  it, 
making  their  home  at  unusual  elevations  with  no  dis- 
comfort to  themselves.  Deer  range  to  heights  where 
the  barometric  pressure  is  but  three  fifths  that  of  their 
generic. habitat.  Bear  do  the  like,  the  brown  bear  of 
northern  American  sea-level  being  here  met  with  two 
miles  above  it.  Nor  is  either  animal  a  depauperate 
form.  Man'  himself  contrives  to  live  in  comfort  and 
propagate  his  kind  where  at  first  he  finds  it  hard  to 
breathe.  Nor  are  these  valiant  exceptions ;  '  as  Mer- 
riam  has  ably  shown  in  his  account  of  the  San  Francisco 
peak  region  for  the  Smithsonian  Institution — a  most  in- 
teresting, report,  by  the  way  —  the  other  animals  are 
equally  adaptive  to  the  zones  of  more  northern  lati- 
tudes on  the  American  continent,  zones  paralleled  in 
their  flora  and  fauna  by  the  zones  of  altitude  up  this 
peak.  All  which  shows  that  paucity  of  air  is  nothing 
like  the  barrier  to  life  we  ordinarily  suppose  and  is  not 
for  an  'instant  to  be  compared  with  dearth  of  water. 
If  in  a  comparatively  short  time  an  animal  or  plant 


CHAP,  ii  A   DEPAETURE-POINT  19 

accustomed  to  thirty  inches  of  barometric  pressure  can 
contrive  to  subsist  sensibly  unchanged  at  eighteen,  it 
would  be  rash  to  set  limits  to  what  time  may  not  do. 
And  this  the  more  for  another  instructive  fact  discov- 
ered in  this  region  by  Merriam :  that  the  existence  of 
a  species  was  determined  not  by  the  mean  tempera- 
ture of  its  habitat  but  by  the  maximum  temperature 
during  the  time  of  procreation.  A  short  warm  season 
in  summer  alone  decides  whether  the  species  shall 
survive  and  flourish;  that  it  has  afterward  to  hiber- 
nate for  six  months  at  a  time  does  not  in  the  least 
negative  the  result. 

That  the  point  of  departure  should  thus  prove  of 
twofold  importance,  speeding  the  observer  on  his 
journey  and  furnishing  him  with  a  vade  mecum  on 
arrival,  is  as  curious  as  opportune.  Without  such 
furtherance,  to  the  bodily  eye  on  the  one  hand  and 
the  mind's  eye  on  the  other,  the  voyage  were  less  con- 
clusive in  advent  and  less  satisfactory  in  attent. 


CHAPTER   III 

A  BIRD'S-EYE  VIEW  OF  PAST  MARTIAN  DISCOVERY 

WITH  Mars  discovery  has  from  the  start  waited  on 
apparent  disk.  To  this  end  every  optical  ad- 
vance has  contributed  from  the  time  of  Galileo's  opera- 
glass  to  the  present  day.  For  apparent  distance  stands 
determined  by  the  size  of  the  eye.  But  although  it 
is  the  telescopic  eye  that  has  increased,  not  the  distance 
that  has  diminished,  the  effect  has  been  kin  to  being 
carried  nearer  the  planet  and  so  to  a  scanning  of  its  disk 
with  constantly  increasing  particularity.  Mankind  has 
to  all  intents  and  purposes  been  journeying  Marsward 
through  the  years.  Any  historic  account  of  the  planet, 
therefore,  becomes  a  chronicle  of  seeming  bodily  ap- 
proach. 

Perhaps  no  vivider  way  of  making  this  evident  and 
at  the  same  time  no  better  preface  to  the  present  work 
could  be  devised  than  by  putting  before  the  eye  in 
orderly  succession  the  maps  made  of  Mars  by  the  lead- 
ing areographers  of  their  day,  since  the  planet  first 
began  to  be  charted  sixty-five  years  ago.  The  pro- 
cedure is  as  much  as  possible  like  standing  at  the  tele- 
scope and  seeing  the  phenomena  steadily  disclose. 
20 


CHAP,  in    VIEW   OF  PAST  MARTIAN   DISCOVERY     21 

Seen  thus  in  order  the  facts  speak  for  themselves. 
They  show  that  from  first  to  last  no  doubt  concerning 
what  was  seen  existed  in  the  minds  of  those  competent 
to  judge  by  systematic  study  of  the  planet  at  first  hand, 
and  furthermore,  from  their  mutual  corroboration,  that 
this  confidence  was  well  placed.  For,  far  from  there 
being  any  conflict  of  authorities  in  the  case,  those  en- 
titled to  an  opinion  in  the  matter  prove  singularly  at 
one. 

Beginning  with  Maedler  in  1840  the  gallery  of  such 
portraitures  of  the  planet  comprises  those  by  Kaiser, 
Green  and  Schiaparelli,  continued  since  Schiaparelli's 
time  by  the  earlier  ones  of  the  present  writer.  To 
this  list  has  been  added  one  by  Flammarion,  which 
though  not  solely  from  his  own  work  gives  so  just  a 
representation  of  what  was  known  at  the  date,  1876,  as 
to  merit  inclusion.  The  remarkable  drawings  of  Dawes 
and  the  excellent  ones  of  Lockyer  in  1862-1864  were 
never  combined  into  maps  by  the  observers,  and  though 
the  former's  were  so  synthesized  by  Proctor  in  1867, 
the  result  was  conformed  to  what  Proctor  thought  ought 
to  be  and  so  is  not  really  a  transcript  of  the  drawings 
themselves. 

Each  of  the  maps  presented  marked  in  its  day  the 
point  areography  had  reached ;  and  each  tells  its  own 
story  better  than  any  amount  of  text.  They  are 
all  made  upon  Mercator's  projection  and  omit  in 


22  MARS  AND  ITS  CANALS  CHAP,  m 

consequence  the  circumpolar  regions.  The  later  ones 
give,  too,  only  so  much  of  the  surface  as  was  shown  at 
the  opposition  they  record,  for  Mars,  being  tipped  now 
one  way,  now  another,  regards  the  earth  differently  ac- 
cording to  its  orbital  position.  In  comparing  them, 
therefore,  the  equator  must  be  taken  for  medial  line. 
Mercator's  projection  has  been  the  customary  one  for 
portraying  Mars  except  for  such  oppositions  as  chiefly 
disclose  the  arctic  pole.  And  this,  too,  with  a  certain 
poetic  fitness.  For  it  comes  by  right  of  priority  to 
delineation  of  a  new  world;  seeing  that  Mercator  was 
the  first  to  represent  in  a  map  the  mundane  new  world 
in  its  entirety,  by  the  rather  important  addition  of 
North  America  to  the  southern  continent  already 
known,  and  to  give  the  whole  the  title  America  with 
'Ame'  at  the  top  of  the  map  and  'rica'  at  the  bottom. 
In  looking  at  the  maps  it  is  to  be  remembered  that 
they  are  what  we  should  call  upside  down,  south  stand- 
ing at  the  top  and  north  at  the  bottom.  Inverted  they 
show  because  this  is  the  way  the  telescopic  observer  al- 
ways sees  the  planet.  The  disk  would  seem  unnatural 
to  astronomers  were  it  duly  righted.  Just  the  same  do 
men  in  the  southern  hemisphere  look  at  our  own  Earth 
topsy-turvy  according  to  our  view,  the  Sun  being  to 
the  north  of  them  and  the  cold  to  the  south.  Certain 
landmarks  distinguishable  in  all  the  maps  may  serve  for 
specific  introduction.  The  V-shaped  marking  on  the 


CHAP,  in    VIEW  OF  PAST   MARTIAN  DISCOVERY      23 

equator  pointing  to  the  north  is  the  Syrtis  Major,  the 
first  marking  ever  made  out  upon  the  planet  and  drawn 
by  the  great  Huyghens  in  1659.  The  isolated  oval 
patch  in  latitude  26°  south  is  the  Solis  Lacus,  the  pupil 
of  the  eye  of  Mars;  while  the  forked  bay  on  the 
equator,  discovered  by  Dawes,  is  the  Sabaeus  Sinus, 
the  dividing  tongue  of  which,  the  Fastigium  Aryn, 
has  been  taken  for  the  origin  of  longitudes  on  Mars. 

Twelve  maps  go  to  make  the  series.  They  are 
as  follows:  — 

MAKER  DATE 

I.     Map  of  Beer  and  Maedler      ....  1840 

II.        "     "  Kaiser 1864 

III.  "     "  Flammarion  (Resume)       .     .  1876 

IV.  "     "  Green 1877 

V.        "      "  Schiaparelli 1877 

VI.  "  "  "  1879 

VII.  "  "  "  1881 

VIII.  "  "  "  1884 

IX.  "  "  Lowell 1894 

X.  "  "       "         1896 

XL  "  "       "         1901 

XII.  "  "       "         1905 

If  these  maps  be  carefully  compared  they  will  be 
found  quite  remarkably  confirmatory  each  of  its  prede- 
cessor. To  no  one  will  their  inter-resemblance  seem 
more  salient  than  to  draughtsmen  themselves.  For 
none  know  better  how  surprisingly,  even  when  two 


24  MARS   AND  ITS  CANALS  CHAP,  m 

men  have  the  same  thing  under  their  very  noses  to  copy, 
their  two  versions  will  differ.  Judgment  of  position 
and  of  relative  size  is  one  cause  of  variation ;  focusing 
of  the  attention  on  different  details  another.  What 
slight  discrepancies  affect  the  maps  are  traceable  to 
these  two  human  imperfections.  Maps  IV  and  V 
make  a  case  in  point:  it  was  to  his  new-found  canals 
that  Schiaparelli  gave  heed  to  the  neglect  of  a  due  ton- 
ing of  his  map ;  while  Green,  less  keen-eyed  but  more 
artistic,  missed  the  delicate  canaliform  detail  to  make 
a  speaking  portraiture  of  the  whole. 

Amid  the  remarkable  continuity  of  progression  here 
shown,  in  which  each  map  will  be  seen  to  be  at  once  a 
review  and  an  advance,  we  may,  nevertheless,  distin- 
guish three  stages  in  the  perception  of  the  phenomena. 
Thus  we  may  mark :  — 

I.    A  period  of  recognition  of  larger  markings 

only; 1840-1877 

II.   A  period  of  detection  of  canals  intersecting 

the  bright  regions  or  lands;    ....     1877-1892 
III.    A  period  of  detection  of  canals  traversing 
the  '  seas '  and  of  oases  scattered  over 
the  surface; 1892-1905 

Each  period  is  here  represented  by  four  charts;  and 
each  expresses  the  result  of  a  more  minute  and  intimate 
acquaintance  with  the  disk  than  was  possible  to  the  one 
that  went  before.  To  realize,  however,  how  accurate 


CHAP,  in     VIEW   OF  PAST   MARTIAN   DISCOVERY     25 

each  was  according  to  his  lights  it  is  only  necessary 
to  have  the  seeing  grow  steadily  better  some  evening 
as  one  observes.  He  will  find  himself  recapitulating 
in  his  own  person  the  course  taken  by  discovery  for 
all  those  who  went  before,  and  in  the  lapse  of  an  hour 
live  through  the  observational  experience  of  sixty 
years;  in  much  the  same  way  that  the  embryological 
growth  of  an  individual  repeats  the  development  his- 
torically of  the  race. 

Two  verses  of  Ovid,  which  the  poet  puts  into  the 
mouth  of  Pythagoras,  outline  with  something  like 
prophetic  utterance  the  special  discoveries  which  mark 
the  three  periods  apart.  Ovid  makes  Pythagoras  say 
of  the  then  world : — 

Vidi  ego,  quod  fuerat  quondam  solidissima  tellus 
Esse  fretum ;  vidi  f actas  ex  aequore  terras  ; 

—  OVID,  Metamorphoses  XV,  262. 

(Where  once  was  solid  ground  I've  seen  a  strait; 
Lands  I've  seen  made  from  out  the  sea.) 

True  as  the  verses  are  of  Earth,  the  poet  could  not  have 
penned  them  otherwise  had  he  meant  to  record  the 
course  of  astronomic  detection  on  Mars.  For  they 
sound  like  a  presentiment  of  the  facts.  A  surface 
thought  at  first  to  be  part  land,  part  water ;  the  land 
next  seen  to  be  seamed  with  straits ;  and  lastly  the  sea 
made  out  to  be  land.  Such  is  the  history  of  the  sub- 
ject, and  words  could  not  have  summed  it  more  sue- 


26  MARS   AND  ITS   CANALS  CHAP,  m 

cinctly.  "Vidi  ego,  quod  fuerat  quondam  solidissima 
tellus  esse  fretum  "  rings  like  Schiaparelli's  own  an- 
nouncement of  the  discovery  of  the  'canals.'  Indeed, 
I  venture  to  believe  he  would  have  made  it  had  he 
chanced  to  recall  the  verse.  So  "vidi"  factas  ex 
aequore  terras"  tells  what  has  since  been  learned  of 
the  character  of  the  seas. 

Of  the  three  periods  the  first  was  that  of  the  main  or 
fundamental  markings  only.  It  came  in  with  Beer 
and  Maedler,  the  inaugurators  of  areography.  That 
they  planned  and  executed  their  survey  with  but  a 
four-inch  glass  shows  that  there  is  always  room  for 
genius  at  the  top  of  any  profession  and  that  instruments 
are  not  for  everything  in  its  instrumentality.  Up  to 
their  day  the  reality  of  the  planet's  features  had  been 
questioned  by  some  people  in  spite  of  having  been 
certainly  seen  and  drawn  by  Huyghens  and  others. 
Beer  and  Maedler's  labors  proved  them  permanent 
facts  beyond  the  possibility  of  dispute. 

The  second  period  was  the  period  of  the  discovery  of 
the  now  famous  canals,  —  a  new  era  in  the  study  of 
Mars  opened  by  Schiaparelli  in  1877  (Map  V).  Un- 
suspicious of  what  he  was  to  stumble  on,  he  seized  the 
then  favorable  opposition  to  make,  as  he  put  it,  a 
geodetic  survey  of  the  planet's  surface.  He  hoped  this 
undertaking  feasible  to  the  accuracy  of  micrometric 
measurement.  His  hopes  did  not  belie'  him.  He 


Map  I.    Beer  and  Maedler,  1840. 


Map  II.    Kaiser,  1864. 
(From  Flammariou's  Mars.) 


Map  III.    Resume  by  Flaramarion,  1876. 
(From  Flammarion's  Mars.) 


Map  IV.    Green,  1877. 
(From  Flammarion's  Mars.) 


CHAP,  in     VIEW  OF   PAST   MARTIAN  DISCOVERY    27 

found  that  it  was  possible  to  measure  his  positions  with 
sufficient  exactness  to  make  a  skeleton  map  on  which 
to  embody  the  markings  in  detail  —  and  thus  to  give 
his  map  vertebrate  support.  But  in  the  course  of  his 
work  he  became  aware  of  hitherto  unrecognized  liga- 
ments connecting  the  seas  with  one  another.  Instead 
of  displaying  a  broad  unity  of  face  the  bright  areas 
appeared  to  be  but  groundwork  for  streaks.  The 
streaks  traversed  them  in  all  directions,  tesselating  the 
continents  into  a  tile  work  of  islands.  Such  mosaic  was 
not  only  new,  but  the  fashion  of  the  thing  was  of  a 
new  order  or  kind.  Straits,  however,  Schiaparelli  con- 
sidered them  and  gave  them  the  name  canali,  or  chan- 
nels. How  unfamiliar  and  seemingly  impossible  the 
new  detail  was  is  best  evidenced  by  the  prompt  and 
unanimous  disbelief  with  which  it  was  met. 

Unmoved  by  the  universal  scepticism  which  rewarded 
what  was  to  prove  an  epoch-making  discovery,  Schia- 
parelli went  on,  in  the  judgment  of  his  critics,  from  bad 
to  worse  —  for  in  1879  (Map  VI)  he  took  up  again  his 
scrutiny  of  the  planet  to  the  detecting  of  yet  more  par- 
ticularity. He  re-observed  most  of  his  old  canals  and 
discovered  half  as  many  more;  and  as  his  map  shows 
he  perceived  an  increased  regularity  in  his  lines. 

In  1881-1882  (Map  VII)  he  attacked  the  planet  again 
and  with  results  yet  further  out  of  the  common.  His 
lines  were  still  there  with  more  beside.  If  they  had 


28  MAES   AND   ITS   CANALS  CHAP,  m 

looked  strange  before,  they  now  appeared  positively 
unnatural.  Not  content  with  a  regularity  which 
seemed  to  the  sceptics  to  preclude  their  being  facts,  he 
must  needs  see  them  now  in  duplicate.  To  the  eyes  of 
disbelief  this  was  the  crowning  stroke  of  factitiousness. 

In  consequence  no  end  of  adverse  criticism  was 
heaped  upon  his  observations  by  those  who  could  not 
see.  But  curiously  enough,  —  what  did  not  attract 
attention,  —  the  blindness  of  the  critics  was  as  much 
mental  as  bodily.  For  they  failed  to  perceive  that 
the  very  unnaturalness  which  seemed  to  them  to  dis- 
credit his  observations  really  proved  their  genuineness. 
His  discoveries  were  so  amazing  that  any  change  in 
strangeness  simply  went  to  confirm  the  universal  scep- 
ticism and  clouded  logic.  Yet  properly  viewed,  a 
pregnant  deduction  stands  forth  quite  clearly  on  a 
study  of  the  maps. 

On  comparing  maps  V,  VI  and  VII  an  eye  duly 
directed  is  struck  by  a  difference  in  the  aspect  of  the 
lines.  In  his  first  map  the  'canals 'are  depicted  sim- 
ply as  narrow  winding  streaks,  hardly  even  roughly 
regular  and  by  no  means  such  departures  from  the 
plausible  as  to  lie  without  the  communicatory  pale. 
Indeed,  to  a  modern  reader  prepared  beforehand  for 
geometric  construction  they  will  probably  appear  no 
'canals'  at  all.  Certainly  the  price  of  acceptance  was 
not  a  large  one  to  pay.  But  like  that  of  the  Sibylline 


CHAP,  in    VIEW  OF  PAST  MARTIAN   DISCOVERY     29 

Books  it  increased  with  putting  off.  What  he  offered 
the  public  in  1879  was  much  more  dearly  to  be  bought. 
The  lines  were  straighter,  narrower,  and  in  every  way 
less  natural  than  they  had  seemed  two  years  before. 
In  1881-1882  they  progressed  still  more  in  unaccount- 
ability.  They  had  now  become  regular  rule  and  com- 
pass lines,  as  straight,  as  even,  and  as  precise  as  any 
draughtsman  could  wish  and  quite  what  astronomic 
faith  did  not  desire.  Having  thus  donned  the  char- 
acter, they  nevermore  put  it  off. 

Now,  this  curious  evolution  in  depiction  points, 
rightly  viewed,  to  an  absence  of  design.  It  shows  that 
Schiaparelli  started  with  no  preconceived  idea  on  the 
subject.  On  the  contrary,  it  is  clear  that  he  shared  to 
begin  with  the  prevailing  hesitancy  to  accept  anything 
out  of  the  ordinary.  Nor  did  he  overcome  his  reluc- 
tance except  as  by  degrees  he  was  compelled.  For  the 
canals  did  not  change  their  characteristics  from  one 
opposition  to  another;  the  eye  it  was  that  learned  to 
distinguish  what  it  saw,  and  the  brain  made  better 
report  as  it  grew  familiar  with  the  messages  sent  it. 
In  other  words,  it  is  patent  from  these  successive  maps 
that  the  geometrical  character  of  the  'canals'  was 
forced  upon  Schiaparelli  by  the  things  themselves, 
instead  of  being,  as  his  critics  took  for  granted,  foisted 
on  them  by  him.  We  have  since  seen  the  regularity 
of  the  canals  so  undeniably  that  we  are  not  now  in  need 


30  MARS  AND   ITS   CANALS  CHAP,  m 

of  such  inferential  support  to  help  us  to  the  truth ;  but 
too  late,  as  it  is,  to  be  of  controversial  moment  the  de- 
duction is  none  the  less  of  some  corroboratory  force. 

With  the  third  period  enters  what  has  been  done  since 
Schiaparelli's  time.  For  that  master  was  obliged, 
from  failing  sight,  to  close  his  work  with  the  opposition 
of  1890.  In  1892  W.  H.  Pickering  at  Arequipa  was  the 
chief  observer  of  the  planet  and  made  two  important 
discoveries :  one  was  the  detection  of  small  round  spots 
scattered  over  the  surface  of  the  planet  and  connected 
with  the  canal  system;  the  other  the  perception  of 
what  seemed  to  him  more  or  less  irregular  lines  travers- 
ing the  Mare  Erythraeum.  Both  were  notable  detec- 
tions. The  first  set  of  phenomena  he  called  lakes, 
the  second  river-systems,  sometimes  schematically 
'canals,'  but  without  committing  himself  to  canaliform 
characteristics  as  his  drawings  make  clear.  The  same 
phenomena  were  seen  at  that  opposition  at  the  Lick, 
by  Schaeberle,  Barnard  and  others,  and  called  streaks. 
These  discoveries  took  from  the  maria  their  supposed 
character  of  seas  —  a  most  important  event  in 
knowledge  of  Mars. 

The  next  advance  was  the  detection  at  Flagstaff 
in  1894  of  their  canaliform  characteristics  by  my  then 
assistant  Mr.  Douglass,  who  in  place  of  the  irregu- 
lar streaks  and  river-systems  of  his  predecessors 
found  the  seas  to  be  crossed  by  lines  as  regular  and 


Map  IX.    Lowell, 


MapX.    Lowell, 


Map  XI.    Lowell,  1901. 


VH  !  '/^T^-.^r  ••—   ^"^TOv^ '  !^X*P>  x  \ 

'i-y  £     •    v,k^ 


VIEW  OF  PAST   MARTIAN  DISCOVERY     31 

as  regularly  connected  as  the  canals  in  the  light 
regions.  To  him  they  appeared  broad  and  ill 
denned,  but  so  habitually  did  to  him  the  canals  in  the 
light  areas,  while  for  directness  and  uniformity  the  one 
set  showed  as  geometrically  perfect  as  the  other.  All 
the  dark  maria  of  the  southern  hemisphere  he  found  to 
be  laced  with  them  and  that  they  formed  a  network 
over  the  dark  regions,  counterparting  that  over  the 
light.  Still  more  significant  was  the  fact  that  their 
points  of  departure  coincided  with  the  points  of  arrival 
of  the  bright-region  canals,  so  that  the  two  connected 
to  form  in  its  entirety  a  single  system.  After  the  pub- 
lication of  his  results  (Lowell  Observatory  Annals, 
Volume  I,  1895)  Schiaparelli  identified  some  of  those 
in  the  Syrtis  with  what  he  had  himself  seen  there  in 
1888  (Memoria,  VI,  1899),  though  his  own  had  not  been 
sufficiently  well  seen  of  him  to  impress  him  as  canals. 
Of  other  additions  to  our  knowledge  since  made  by 
the  writer  the  present  book  treats;  as  also  of  the 
theory  they  originally  suggested  to  him  and  which  his 
later  observations  "have  only  gone  to  confirm. 


CHAPTER   IV 

THE    POLAR   CAPS 

A  LMOST  as  soon  as  magnification  gives  Mars  a 
•^••*-  disk  that  disk  shows  markings,  white  spots  crown- 
ing a  globe  spread  with  blue-green  patches  on  an  orange 
ground.  The  smallest  telescope  is  capable  of  this  far- 
off  revelation ;  while  with  increased  power  the  picture 
grows  steadily  more  articulate  and  full.  With  a  two 
and  a  quarter  inch  glass  the  writer  saw  them  thirty-five 
years  ago. 

After  the  assurance  that  markings  exist  the  next 
thing  to  arrest  attention  is  that  these  markings  move. 
The  patches  of  color  first  made  out  by  the  observer  are 
shortly  found  by  him  to  have  shifted  in  place  upon  the 
planet.  And  this  not  through  mistake  on  his  part  but 
through  method  in  the  phenomena ;  for  all  do  it  alike. 
In  orderly  rotation  the  features  make  their  appearance 
upon  the  body's  righthand  limb  (in  the  telescopic 
image),  travel  across  the  central  meridian  of  the  disk 
and  vanish  over  its  lefthand  border.  One  follows  an- 
other, each  rising,  culminating  and  setting  in  its  turn 
under  the  observer's  gaze.  A  constantly  progressing 
panorama  passes  majestically  before  his  sight,  new 


CHAP,  iv  THE   POLAR  CAPS  33 

objects  replacing  the  old  with  a  march  so  steady  and 
withal  so  swift  that  a  few  minutes  will  suffice  to  mark 
unmistakably  the  fact  of  such  procession.  But  for 
all  this  ceaseless  turning  under  his  gaze,  after  a  certain 
lapse  of  time  it  is  evident  that  the  same  features  are 
being  shown  him  over  again.  With  such  recognition 
of  recurrence  comes  the  first  advance  toward  acquaint- 
ance with  the  Martian  world.  For  that  in  all  their 
journeying  their  configuration  alters  not,  proves  them 
permanent  in  place,  part  and  parcel  of  the  solid  surface 
of  that  other  globe.  This  surface,  then,  lies  exposed 
to  view  and  by  its  turning  shows  itself  subject,  like 
our  earth,  to  the  vicissitudes  of  day  and  night. 

In  such  self-exposure  Mars  differs  from  all  the  four 
great  planets,  Jupiter,  Saturn,  Uranus  and  Neptune. 
Features,  indeed,  are  apparent  on  the  first  two  of  these 
globes  and  dimly  on  the  other  two  as  well,  but  they  lack 
the  stability  of  the  Martian  markings.  They  are  forever 
exchanging  place.  In  the  case  of  Jupiter  what  we  see  is 
undoubtedly  a  cloud-envelop  through  which  occasional 
glimpses  may  possibly  be  caught  of  a  chaotic  nucleus 
below.  With  Saturn  it  is  the  same ;  and  the  evidence 
is  that  the  like  is  true  of  Uranus  and  Neptune.  What 
goes  on  under  their  great  cloud  canopies  we  can  only  sur- 
mise. With  Mars,  however,  we  are  not  left  to  imagina- 
tion in  the  matter  but  so  far  as  our  means  permit  can 
actually  observe  what  there  takes  place.  Except  for 


34  MARS  AND  ITS  CANALS  CHAP,  iv 

distance,  which,  through  science,  year  by  year  grows 
less,  it  is  as  if  we  hovered  above  the  planet  in  a  bal- 
loon, with  its  various  features  spread  out  to  our  gaze 
below. 

Attention  shows  these  areographic  features  to  be  on 
hand  with  punctual  precision  for  their  traverse  of  the 
disk  once  every  twenty-four  hours  and  thirty-seven 
minutes.  For  over  two  hundred  years  this  has  been 
the  case,  their  untiring  revolutions  having  been  watched 
so  well  that  we  know  the  time  they  take  to  the  nicety 
of  a  couple  of  hundredths  of  a  second.  We  thus  become 
possessed  of  a  knowledge  of  the  length  of  the  Martian 
day  and  it  is  not  a  little  interesting  to  find  that  it  very 
closely  counterparts  in  duration  our  own,  being  only 
one  thirty-fifth  the  longer  of  the  two.  We  also  find 
from  the  course  the  markings  pursue  the  axis  about 
which  they  turn ;  and  just  as  the  period  of  the  rotation 
tells  us  the  length  of  the  Martian  day  so  the  tilt  of  the 
axis,  taken  in  connection  with  the  form  of  the  orbit, 
determines  the  character  of  the  Martian  seasons.  Here 
again  we  confront  a  curious  resemblance  in  the  cir- 
cumstances of  the  two  planets,  for  the  tilt  of  the  equator 
to  the  plane  of  the  orbit  is  with  Mars  almost  precisely 
what  it  is  for  the  Earth.  The  more  carefully  the  two  are 
measured  the  closer  the  similitude  becomes.  Sir  William 
Herschel  made  the  Martian  28°,  Schiaparelli  reduced 
this  to  25°,  and  later  determination  by  the  writer 


CHAP,  iv  THE  POLAR  CAPS  35 

puts  it  nearer  24°.  The  latter  is  the  one  now  adopted 
in  the  British  Nautical  Almanac  for  observers  of 
the  planet.  This  is  a  very  close  parallelism  indeed; 
so  that  in  general  character  the  Martian  seasons 
"are  nearly  the  counterpart  of  ours.  In  length,  how- 
ever, they  differ;  first  because  the  year  of  Mars  is 
almost  double  the  length  of  the  terrestrial  one  and 
secondly  because  from  the  greater  ellipticity  of  Mars' 
orbit  the  seasons  are  more  unequal  than  is  the  case  with 
us,  some  being  run  through  with  great  haste,  others 
being  lingered  on  a  disproportionate  time.  It  is  usual 
on  the  Earth  to  consider  spring  as  the  period  from  the 
vernal  equinox,  about  March  21,  to  the  summer  solstice, 
about  June  20 ;  summer  as  lasting  thence  to  the  au- 
tumnal equinox;  autumn  from  this  latter  date,  about 
September  20,  to  the  winter  solstice  on  December  21 ; 
and  winter  from  that  point  on  to  the  next  spring 
equinox  again.  On  this  division  our  seasons  in  the 
northern  hemisphere  last  respectively :  spring,  91  days ; 
summer,  92  days;  autumn,  92  days;  and  winter,  90 
days.  On  Mars  these  become,  reckoned  in  our  days : 
spring,  199  days;  summer  183  days;  autumn,  147 
days;  and  winter,  158  days.  If  we  had  counted  them 
in  Martian  days  they  would  have  totaled  about  one 
thirty-fifth  less  in  number  each. 

In  its  days  and  seasons,  then,  Mars  is  wonderfully 
like  the  Earth;   except  for  the  length  of  the  year  we 


36  MARS   AND  ITS   CANALS  CHAP,  iv 

should  hardly  know  the  difference  in  reckoning  of  time 
could  we  some  morning  wake  up  there  instead  of  here. 
Only  in  one  really  unimportant  respect  should  we  feel 
strange;  in  months  we  should  find  ourselves  turned 
topsy-turvy.  But  lunations  have  nothing  to  do  with 
climate  nor  with  the  alternation  between  night  and 
day;  and  in  these  two  important  respects  we  should 
certainly  feel  at  home. 

Though  the  axis  could  be  determined  by  the  daily 
march  of  any  marking  and  thus  the  planet's  tropic, 
temperate  and  polar  regions  marked  out,  the  process 
is  made  easier  by  the  presence  of  white  patches  cov- 
ering the  planet's  poles  and  known,  in  consequence, 
as  the  polar  caps.  It  is  from  measures  of  the  patches 
that  the  position  of  the  Martian  poles  has  actually 
been  determined.  These  polar  caps  are  exactly  analo- 
gous in  general  position  to  those  which  bonnet  our  own 
Earth.  They  reproduce  the  appearance  of  the  ice  and 
snow  of  our  arctic  and  antarctic  regions  seen  from  space, 
in  a  very  remarkable  manner.  In  truth  they  are  things 
of  note  in  more  ways  than  one  and  would  claim  prece- 
dence on  many  counts.  Priority  of  recognition,  how- 
ever, alone  entitles  them  to  premier  consideration. 
Among  the  very  first  of  the  disk's  detail  to  be  made 
out  by  man,  they  justly  demand  description  first. 

With  peculiar  propriety  the  polar  caps  have  thus 
the  pas.  Not  only  do  they  stand  first  in  order  of 


CHAP,  iv  THE   POLAR  CAPS  37 

visibility,  but  they  prove  to  occupy  a  like  position 
logically  when  it  comes  to  an  explanation  of  the 
planet's  present  physical  state.  It  is  not  matter  of 
hazard  that  the  most  evident  of  all  the  planet's  mark- 
ings should  also  be  the  most  fundamental,  the  fountain- 
head  from  which  everything  else  flows.  It  is  of  the 
essence  of  the  planet's  condition  and  furnishes  the  key 
to  its  comprehension.  The  steps  leading  to  this  con- 
clusion are  as  interesting  as  they  are  cogent.  They 
start  at  the  polar  caps'  visibility.  For  their  size  first 
riveted  man's  attention  and  then  attention  to  them 
disclosed  that  most  vital  of  the  characteristics  of  the 
planet's  surface:  change. 

Just  as  almost  all  of  the  features  we  note  are  per- 
manent in  place,  showing  that  they  belong  to  the  surface, 
so  are  they  all  impermanent  in  character.  Change 
is  the  only  absolutely  unchanging  thing  except  position 
about  the  features  the  planet  presents  to  view.  It 
was  in  the  aspect  of  the  polar  caps  that  this  important 
fact  first  came  to  light.  Not  only  did  they  thus  initially 
instance  a  general  law,  they  have  turned  out  to  make 
it;  for  by  themselves  changing  they  largely  cause 
change  in  all  the  rest.  But  for  a  long  time  they  alone 
exemplified  its  workings.  To  Sir  William  Herschel 
we  owe  the  first  study  of  their  change  in  aspect.  This 
eminent  observer  noted  that  their  varying  size  was 
subject  to  a  regular  rhythmic  wax  and  wane  timed  to 


MARS  AND  ITS  CANALS  CHAP,  iv 

course  of  the  seasons  of  the  planet's  year.  The 
]  caps  increased  in  the  winter  of  their  hemisphere  and 
decreased  in  its  summer  and  being  situate  in  opposite 
hemispheres  they  did  this  alternately  with  pendulum- 
likeprecision.  His  observations  were  soon  abundantly 
confirmed,  for  the  phenomena  take  place  upon  a  vast 
scale  and  are  thus  easy  of  recognition.  At  their  maxi- 
mum spread  the  caps  cover  more  than  one  hundred  times 
as  much  ground  as  when  they  have  shrunk  to  their 
minimum.  In  the  depth  of  winter  they  stretch  over 
much  more  than  the  polar  zone,  coming  down  to  60° 
and  even  50°  of  latitude  north  or  south  as  the  case  may 
be,  thence  melting  till  by  midsummer  they  span  only 
^fiye  or  six  degrees  across. 

In  this  they  bear  close  analogue  to  the  behavior 
of  our  own.  Ours  would  show  not  otherwise  were  they 
viewed  from  the  impersonal  standpoint  of  space.  Very 
little  telescopic  aid  suffices  to  disclose  the  Martian  polar 
phenomena  in  this  their  more  salient  characteristics 
and  convince  an  observer  of  their  likeness  to  those  of  the 
earth.  Any  one  may  note  what  is  there  going  on  by 
successive  observations  of  the  planet  with  a  three-inch 
glass.  Nor  is  the  change  by  any  means  slow.  A  few 
days  at  the  proper  Martian  season,  or  at  most  a  couple 
of  weeks,  produces  conspicuous  and  conclusive  altera- 
tions in  the  size  of  these  nightcaps  of  the  planet's 
winter  sleep.  Resembling  our  own  so  well  they  were 


CHAP,  iv  THE  POLAR  CAPS  39 

early  surmised  to  be  of  like  constitution  and  composed, 
therefore,  of  ice  and  snow.  Plausible  on  its  face,  this 
view  of  them  was  generally  adopted  and  common  sense 
has  held  to  it  ever  since.  It  has  encountered,  of  course, 
opposition,  partly  from  very  proper  conservatism, 
but  chiefly  from  that  earth-centred  philosophy  which 
has  doubted  most  advances  since  Galileo's  time,  and 
carbonic  acid  has  been  put  forward  by  this  school  of 
sceptics  to  take  its  place.  We  shall  critically  examine 
both  objections;  the  latter  first,  because  a  certain 
physical  fact  enables  us  to  dispose  of  it  at  once.  In 
casual  appearance  there  is  not  much  to  choose  between 
the  rival  candidates  of  common  sense  and  uncommon 
subtlety,  water  and  frozen  carbonic  acid  gas,  both  being 
suitably  white  and  both  going  and  coming  with  the 
temperature.  But,  upon  closer  study,  in  one  point  of 
behavior  the  two  substances  act  quite  unlike,  and  had 
half  the  ingenuity  been  expended  in  testing  the  theory 
as  in  broaching  it  this  fact  had  come  to  light  to  the 
suggestors  as  it  did  upon  examination  to  the  writer 
and  had  served  as  a  touchstone  in  the  case.  At  pres- 
sures of  anything  like  one  atmosphere  or  less  carbonic 
acid  passes  at  once  from  the  solid  to  the  gaseous  state. 
Water,  on  the  other  hand,  lingers  in  the  intermediate 
stage  of  a  liquid.  Now,  as  the  Martian  cap  melts  it 
shows  surrounded  by  a  deep  blue  band  which  accom- 
panies it  in  its  retreat,  shrinking  to  keep  pace  with  the 


40  MARS   AND  ITS   CANALS  CHAP,  iv 

shrinkage  in  the  cap.  This  is  clearly  the  product  of  the 
disintegration  since  it  waits  so  studiously  upon  it.  The 
substance  composing  the  cap,  then,  does  not  pass  in- 
stantaneously or  anything  like  it  from  the  solid  to  the 
gaseous  condition. 

This  badge  of  blue  ribbon  about  the  melting  cap, 
therefore,  conclusively  shows  that  carbonic  acid  is 
not  what  we  see  and  leaves  us  with  the  only  alternative 
we  know  of :  water. 


CHAPTER  V 

BEHAVIOR   OF   THE    POLAR   CAPS 

A  SSURED  by  physical  properties  that  our  visual 
appearances  are  quite  capable  of  being  what  they 
seem  we  pass  to  the  phenomena  of  the  cap  itself.  Like 
as  are  the  polar  caps  of  the  two  planets  at  first  regard, 
upon  further  study  very  notable  differences  soon  dis- 
close themselves  between  the  earthly  and  the  Martian 
ones;  and  these  serve  to  give  us  our  initial  hint  of  a 
different  state  of  things  over  there  from  that  with 
which  we  are  conversant  on  Earth. 

To  begin  with,  the  limits  between  which  they  fluc- 
tuate are  out  of  all  proportion  greater  on  Mars.  It  is 
not  so  much  in  their  maxima  that  the  ice-sheets  of  the 
two  planets  vary.  Our  own  polar  caps  are  much 
larger  than  we  think ;  indeed,  we  live  in  them  a  good 
fraction  of  the  time.  Our  winter  snows  are  in  truth 
nothing  but  part  and  parcel  of  the  polar  cap  at  that 
season.  Now,  in  the  northern  hemisphere  snow  covers 
the  ground  at  sea-level  more  or  less  continuously  down 
to  50°  of  latitude.  It  stretches  thus  far  even  on  the 
western  flanks  of  the  continents,  while  in  the  middle  of 
them  and  on  their  eastern  sides  it  extends  ten  degrees 

41 


42  MARS  AND  ITS  CANALS  CHAP,  v 

farther  yet  during  the  depth  of  winter.  So  that  we 
have  a  polar  cap  which  is  then  ninety  degrees  across. 
In  our  southern  hemisphere  it  is  much  the  same  six 
months  later,  in  the  corresponding  winter  of  its  year. 
On  Mars  at  their  winter  maxima  the  polar  caps  extend 
over  a  similar  stretch  of  latitude.  They  do  so,  how- 
ever, unequally.  The  southern  one  is  considerably  the 
larger.  In  1903,  136  days  after  the  winter  solstice, 
in  the  Martian  calendar  February  27,  it  came  down  in 
longitude  225°  to  44°  of  latitude  and  may  be  taken  to 
have  then  measured  ninety-three  degrees  across;  in 
1905,  121  days  after  the  same  solstice,  it  stretched 
in  longitude  235°  to  latitude  42°,  and  158  days  later, 
in  longitude  221°  to  latitude  41°;  values  which,  sup- 
posing it  to  have  been  round,  imply  for  it  a  diameter 
on  these  occasions  of  ninety-six  and  ninety-seven 
degrees.  It  was  then  February  20  and  March  10 
respectively  of  the  Martian  year.  These  determinations 
of  its  size  at  the  two  oppositions  agree  sufficiently  well 
considering  the  great  tilt  away  from  us  of  the  south 
pole  at  the  time  and  the  horizonward  foreshortening 
of  the  edge  of  the  snow.  It  seems  from  a  consensus 
of  the  measures  to  have  been  some  five  degrees 
wider  in  1903  than  in  1905,  which  may  mean  a  colder 
winter  preceding  the  former  date.  The  cap  was  still 
apparently  without  a  dark  contour  in  both  years, 
showing  that  it  had  not  yet  begun  to  melt. 


South  Polar  Cap. 
(Lowell  Observatory,  1905.) 


CHAP,  v       BEHAVIOR  OF  THE  POLAR  CAPS  43 

Less  has  been  learnt  of  the  northern  cap.  In  1896- 
1897  when  it  was  similarly  presented  skirting  the  other 
rim  of  the  disk,  a  gap  occurred  in  the  observations  corre- 
sponding to  the  time  by  Martian  months  between  Feb- 
ruary 24  and  March  22.  On  the  former  date  the  cap 
came  down  only  to  latitude  55°  in  longitude  352°; 
on  the  subsequent  one  and  for  several  days  after  the 
latitude  of  the  southern  limit  of  the  snow  was  such  as 
to  imply  a  breadth  to  it  of  about  eighty  degrees.  The 
cap  was  now  bordered  by  a  dark  line,  proving  that  melt- 
ing had  already  set  in.  It  cannot,  however,  at  its 
maximum  have  covered  much  more  country  than  this, 
in  view  of  its  lesser  extent  on  February  24. 

Fair  as  our  knowledge  now  is  of  the  dimensions  of  the 
Martian  polar  caps  at  their  maxima,  we  have  much 
more  accurate  information  with  regard  to  their  minima, 
and  this,  too,  was  obtained  much  earlier.  That  we 
should  first  have  known  their  smallest  rather  than  their 
greatest  extent  with  accuracy  may  appear  surprising, 
exactly  the  opposite  being  our  knowledge  of  our  own. 
It  is  not,  however,  so  surprising  as  it  appears,  inas- 
much as  it  is  an  inevitable  consequence  of  the  planet's 
aspect  with  regard  to  the  sun.  When  the  tilt  of  the 
axis  inclines  one  hemisphere  toward  the  sun,  that  hemi- 
sphere's polar  cap  must  melt  and  dwindle,  while  at 
the  same  time  it  is  the  one  best  seen,  the  other  being 
turned  away  from  the  sun  and  therefore  largely 


44  MARS   AND   ITS   CANALS  CHAP,  v 

from  us  as  well ;  so  that  even  such  part  of  the  latter 
as  is  illumined  lies  low  down  toward  the  horizon  of 
the  disk  where  a  slight  change  of  angle  means  a 
great  difference  in  size. 

It  has  thus  come  about  that  both  the  south  and  the 
north  polar  caps  have  been  repeatedly  well  seen  and 
measured  at  their  minimum;  and  the  measures  for 
different  Martian  years  agree  well  with  one  another. 
For  the  northern  cap  six  degrees  in  diameter  is  about 
the  least  value  to  which  it  shrinks.  The  south  one 
becomes  even  smaller,  being  usually  not  more  than  five 
degrees  across,  while  in  1894  it  actually  vanished,  a 
thing  unprecedented.  Its  absence  was  detected  by 
Douglass  at  Flagstaff  and  shortly  after  the  announce- 
ment of  its  disappearance  the  fact  was  corroborated 
by  Barnard  at  the  Lick.  The  position  the  cap  would 
have  occupied  was  at  the  time  better  placed  for  obser- 
vation in  America  than  in  Europe,  inasmuch  as  the 
cap  is  eccentrically  situated  with  regard  to  the  geo- 
graphic pole  and  its  centre  was  then  well  on  the  side 
of  the  disk  presented  to  us  while  in  Europe  it  was  turned 
away.  This,  together  with  the  fact  that  it  undoubtedly 
came  and  went  more  than  once  about  this  time,  ac- 
counts for  its  disappearance  not  having  been  recog- 
nized there,  haze  left  by  it  having  apparently  been 
mistaken  for  the  cap  itself. 

On  Earth  the  minima  are  much  larger.      In  the 


r* 


: 


* 


North  Polar  Cap. 
(Lowell  Observatory,  1905.) 


CHAP,  v       BEHAVIOR   OF  THE  POLAK   CAPS  45 

northern  hemisphere  the  line  of  perpetual  snow  or 
pack-ice  in  longitude  50°  east  runs  about  on  the  80° 
parallel,  including  within  it  the  southern  end  of  Franz 
Joseph  Land.  Opposite  this,  in  longitude  120°  west, 
above  the  North  American  continent,  it  reaches  down 
lower  still  to  75°.  So  that  the  cap  is  then  from  twenty 
to  thirty  degrees  in  diameter.  In  the  southern  hemi- 
sphere it  is  even  larger.  In  longitude  170°  west  the 
land  was  found  by  Ross  to  be  under  perpetual  snow  in 
latitude  72°.  Cook  had  reached  in  longitude  107° 
east  an  impassable  barrier  of  ice  in  latitude  70°  23'. 
The  season  was  then  midsummer,  January  30.  So  that 
we  are  perhaps  justified  in  considering  71°  south  as 
about  the  average  limit  of  perpetual  snow  or  paleo- 
crystic  ice.  This  would  make  the  southern  cap  at  its 
minimum  thirty-eight  degrees  across.  Pack-ice  with 
open  spots  extends  still  farther  north.  The  Pagoda  in 
1845  was  stopped  by  impenetrable  pack-ice  in  south 
latitude  68°  and  the  Challenger  in  1874  encountered 
the  pack  in  latitude  65°  on  the  19th  of  February,  which 
corresponds  about  to  our  19th  of  August,  the  time  at 
which  the  sea  should  be  most  open.  The  limit  of  per- 
petual snow  is  thus  lower  in  the  southern  than  in  the 
northern  hemisphere.  Here  again,  then,  the  two 
minima  differ,  but  in  the  reverse  way  from  what  they 
do  on  Mars. 

From  this  we  perceive  that  the  variations  in  size  of 


46  MARS  AND  ITS   CANALS  CHAP,  v 

the  caps  are  much  more  striking  on  Mars  than  on  the 
Earth  and  that  these  are  due  chiefly  to  the  difference  in 
the  minima,  the  maxima  not  varying  greatly. 

To  explain  these  interesting  diversities  of  behavior 
in  the  several  polar  caps  we  shall  have  to  go  back  a 
little  in  general  physics  in  order  to  get  a  proper  take 
off.  It  is  a  curious  concomitant  of  the  law  of  gravity 
that  the  amount  of  heat  received  by  a  planet  in  passing 
from  any  point  of  its  path  to  a  point  diametrically 
opposite  is  always  the  same  no  matter  what  be  the 
eccentricity  of  the  orbit.  Thus,  a  planet  has  as  many 
calories  falling  upon  it  in  travelling  from  its  vernal 
equinox  to  its  autumnal  as  from  the  autumnal  to  the 
vernal  again,  although  the  time  taken  in  the  one  journey 
be  very  different  from  that  of  the  other.  This  is  due 
to  the  fact  that  the  angle  swept  over  by  the  radius  vec- 
tor, that  is,  the  imaginary  bond  between  it  and  the  sun, 
is  at  all  points  proportional  to  the  amount  of  heat  re- 
ceived; just  as  it  is  of  the  gravity  undergone,  the  two 
forces  radiating  into  space  as  the  inverse  square  of  the 
distance.  Thus  the  heat  received  by  a  point  or  a 
hemisphere,  through  any  orbital  angle,  is  independent 
of  the  eccentricity  of  the  orbit. 

But  it  is  not  independent  of  the  axial  tilt.  For  the 
force  of  the  sun's  rays  is  modified  by  their  obliquity. 
The  amount  of  heat  received  at  any  point  in  consequence 
of  the  tilt  turns  upon  the  position  of  the  point,  and  for 


CHAP,  v       BEHAVIOR   OF   THE   POLAE  CAPS  47 

any  hemisphere  taken  as  a  whole  it  depends  upon  the 
degree  to  which  the  pole  is  tilted  to  the  source  of  heat. 
In  consequence  of  being  more  squarely  presented  to  its 
beams,  the  hemisphere  which  is  directed  toward  the 
sun  and  therefore  is  passing  through  its  summer  season 
gets  far  more  insolation  than  that  which  is  at  the  same 
time  in  the  depth  of  its  winter.  For  a  tilt  of  twenty- 
four  degrees,  the  present  received  value  for  the  axis 
of  Mars,  the  two  hemispheres  so  circumstanced  get 
amounts  of  heat  respectively  in  the  proportion  of 
sixty-three  to  thirty-seven. 

But,  though  the  summer  and  winter  insolation  thus 
differ,  they  are  the  same  for  each  hemisphere  in  turn. 
Consequently  the  mere  amount  of  heat  received  cannot 
be  the  cause  of  any  differences  detected  between  the 
respective  maxima  and  minima  of  the  two  polar 
caps.  If  heat  were  a  substance  which  could  be  stored 
up  instead  of  being  a  mode  of  motion,  the  effect  pro- 
duced would  be  in  accordance  with  the  quantity  ap- 
plied and  the  two  caps  would  behave  alike.  As  it  is 
the  total  amount  has  very  little  to  say  in  the  matter. 

Not  the  amount  of  heat  but  the  manner  in  which  this 
heat  is  made  at  home  is  responsible  for  the  difference 
we  observe.  Now,  though  the  total  amount  is  the 
same  in  passing  from  the  vernal  to  the  autumnal  equinox 
as  from  the  autumnal  to  the  vernal,  the  time  during 
which  it  is  received  in  either  case  varies  from  one  hemi- 


48  MARS   AND  ITS   CANALS  CHAP,  v 

sphere  to  the  other.  It  is  summer  in  the  former  while 
it  is  winter  in  the  latter  and  the  difference  in  the  length 
of  the  two  seasons  due  to  the  eccentricity  of  the  orbit 
makes  a  vast  difference  in  the  result.  Winter  affects 
the  maxima,  summer  the  minima,  attained.  Of  these 
opposite  variations  presented  to  us  by  the  two  caps, 
the  maxima,  the  one  most  difficult  to  detect,  is  the 
easiest  to  explain,  for  the  difference  in  the  maxima 
seems  to  be  due  to  the  surpassing  length  of  the  antarctic 
night. 

Owing  to  the  eccentricity  of  the  orbital  ellipse  pur- 
sued by  Mars  and  to  the  present  position  of  the  planet's 
solstices,  the  southern  hemisphere  is  farther  away  from 
the  sun  during  its  winter  and  is  so  for  a  longer  time. 
The  seasons  are  in  length,  for  the  northern  hemisphere : 
spring,  199  days;  summer,  183  days;  autumn,  147 
days;  and  winter,  158  days;  while  for  the  southern 
hemisphere  they  are :  spring,  147  days;  summer,  158 
days ;  autumn,  199  days ;  and  winter,  183  days.  The 
arctic  polar  night  is  thus  305  of  our  days  long;  the 
antarctic,  382.  Thus  for  77  more  days  than  happens  to 
its  fellow  the  southern  pole  never  sees  the  sun.  Now, 
since  the  total  sunlight  from  equinox  to  equinox  is  the 
same  in  both  hemispheres,  its  distribution  by  days  must 
be  different.  In  the  southern  hemisphere  the  same 
amount  is  crowded  into  a  smaller  compass  in  the 
proportion  of  305  to  382 ;  that  being  that  hemisphere's 


CHAP,  v       BEHAVIOR   OF   THE   POLAR   CAPS  49 

relative  ratio  of  days.  But  since  during  winter  the  cap 
increases,  there  is  a  daily  excess  of  accumulation  over 
dissipation  of  snow  and  each  twenty-four  hours  must 
on  the  average  add  its  tithe  to  the  sum  total.  Since  the 
northern  days  are  the  warmer  each  adds  less  than  do 
the  southern  ones ;  and  furthermore  there  are  fewer  of 
them.  On  both  these  scores  the  amount  of  the  dep- 
osition about  the  northern  pole  should  be  less  than 
about  the  southern  one.  Consequently,  the  snow- 
sheet  there  should  be  the  less  extensive  and  show  a 
relatively  smaller  maximum,  which  explains  what  we 
see. 

With  the  minima  the  action  is  otherwise.  Inasmuch 
as  the  greater  heat  received  during  the  daylight  hours 
by  the  southern  hemisphere  is  exactly  offset  by  the 
shortness  of  its  season,  it  would  seem  at  first  as  if  there 
could  be  no  difference  in  the  total  effect  upon  the  two 
ice-caps. 

But  further  consideration  discloses  a  couple  of  factors 
which  might,  and  possibly  do,  come  in  to  qualify  the 
action  and  account  for  the  observed  effect.  One  is  that 
though  the  total  amount  of  heat  received  is  the  same, 
the  manner  of  its  distribution  differs  in  the  two  hemi- 
spheres. In  the  northern  one  the  time  from  vernal 
to  autumnal  equinox  is  382  days  against  305  in  the 
southern.  Consequently,  the  average  daily  heat  is 
then  five  fourths  more  intense  in  the  southern  hemi- 


50  MAKS  AND   ITS   CANALS  CHAP,  v 

sphere.  Indeed,  it  is  even  greater  than  this  and  nearer 
four  thirds,  because  the  melting  occurs  chiefly  in  the 
spring  and  in  the  first  two  months  of  summer  when  the 
contrast  in  length  of  season  between  the  two  hemi- 
spheres is  at  its  greatest.  Now,  a  few  hotter  days 
might  well  work  more  result  than  many  colder  ones. 
And  this  would  be  particularly  true  of  Mars  where  the 
mean  temperature  is  probably  none  too  much  above  the 
freezing-point  to  start  with.  Ice  consumes  so  much 
caloric  in  the  process  of  turning  into  any  other  state, 
laying  it  by  in  the  form  of  latent  heat  before  it  can 
turn  into  water  and  then  so  much  more  before  this 
water  can  be  converted  into  steam  that  a  good  deal  has 
to  be  expended  on  it  before  getting  any  perceptible 
result.  Once  obtained,  however,  the  heat  is  retained 
with  like  tenacity.  So  that  the  process  works  to 
double  effect !  If  sufficient  heat  be  received  the  ice  is 
first  melted,  then  evaporated  and  finally  formed  into 
a  layer  of  humid  air,  the  humidity  of  which  keeps  it 
warm.  Dry  air  is  unretentive  of  heat,  moist  air  the 
opposite.  And  for  the  melting  of  the  ice-cap  to  pro- 
ceed most  effectively  the  temperature  that  laps  it  about 
must  be  as  high  as  possible  and  kept  so  as  continuously 
as  may  be.  If  between  days  it  be  allowed  to  fall  too 
low  at  night  much  caloric  must  needs  be  wasted  in 
simply  raising  the  ice  again  to  the  melting-point.  This 
a  blanket  of  warm  air  tends  to  prevent,  and  this  again 


CHAP,  v       BEHAVIOR   OF  THE  POLAR   CAPS  51 

is  brought  about  by  a  few  hot  days  rather  than  by 
many  colder  ones.  It  is  not  all  the  heat  received  that 
becomes  effective  but  the  surplus  heat  above  a  certain 
point.  The  gain  in  continuity  of  action  thus  brought 
about  is  somewhat  like  that  exhibited  between  the 
running  of  an  express  and  an  accommodation  train. 
To  reach  its  destination  in  a  given  time  the  former 
requires  far  less  power  because  it  does  not  have  to  get 
up  speed  again  after  each  arrest.  Thus  the  whole  effect 
in  melting  the  snow  would  be  greater  upon  that  hemi- 
sphere whose  summer  happens  to  be  the  more  intense. 
The  greater  swing  in  size  of  the  cap  most  exposed  to 
the  effects  of  the  eccentricity  is,  then,  the  necessary 
result  of  circumstances  when  the  precipitation  is  not 
too  great  to  be  nearly  carried  off  by  the  subsequent 
dissipation.  This  is  the  state  of  things  on  Mars  and 
the  second  of  the  factors  above  referred  to.  On  the 
Earth  as  we  have  seen  the  polar  caps  are  somewhat 
larger  at  their  maximum  and  very  much  so  at  their 
minimum.  Now,  this  is  just  what  should  happen 
were  the  precipitation  increased.  Suppose,  for  exam- 
ple, that  the  amount  of  precipitation  were  to  increase 
while  the  amount  of  summer  melting  remained  the 
same,  and  this  would  be  the  case  if  the  vapor  in  the  air 
augmented  for  one  cause  or  another,  and  the  result 
of  each  fresh  deposit  was  locked  up  in  snow.  After 
a  certain  point  the  cap  would  grow  in  depth  rather  than 


52  MARS  AND   ITS  CANALS  CHAP,  v 

in  extension;  the  winter  deposit  would  be  thicker 
but  the  summer  evaporation  would  remain  the  same. 
Now,  if  this  occurred,  it  is  evident  that  the  minimum 
size  of  the  cap  would  increase  relatively  much  faster 
than  the  maximum,  and  furthermore,  that  the  relative 
increase  of  the  minimum  in  the  two  caps  would  be 
greatest  for  that  which  had  seasons  of  extremes. 
The  result  we  see  in  the  case  of  the  Earth.  In  the  arctic 
cap,  where  in  consequence  of  the  eccentricity  of  the 
orbit  the  winter  is  shorter,  the  maximum  is  less  than 
in  the  antarctic  and  this  extra  amount  of  precipitation 
cannot  be  wholly  done  away  with  in  its  intenser  sum- 
mer, so  that  the  minimum  too  is  greater  there. 

We  reach,  then,  this  interesting  conclusion.  We  find 
that  eccentricity  of  orbit  by  itself  not  only  causes  no 
universal  glaciation  in  the  hemisphere  which  we  should 
incidentally  suppose  likely  to  show  it,  but  actually 
produces  the  opposite  result,  in  more  than  offsetting  by 
summer  proximity  what  winter  distance  brings  about. 
To  cause  extensive  glaciation  we  must  have,  in  addi- 
tion to  favorable  eccentricity,  a  large  precipitation. 
With  these  two  factors  combined  we  get  an  ice  age,  but 
not  otherwise.  The  result  has  an  important  bearing 
on  geologic  glacial  periods  and  their  explanation. 

Once  formed,  an  ice-sheet  cools  everything  about  it 
and  chills  the  climate  of  its  hemisphere.  It  is  a  per- 
petual storehouse  of  cold.  Mars  has  no  such  general 


CHAP,  v       BEHAVIOR   OF   THE  POLAR   CAPS  53 

glaciation  in  either  hemisphere,  and  the  absence  of  it, 
which  is  due  to  lesser  precipitation,  together  with  the 
clearness  of  its  skies,  accounts  for  the  warmth  which 
the  surface  exhibits  and  which  has  been  found  so  hard 
Hitherto  to  interpret.  Could  our  earth  but  get  rid  of 
its  oceans,  we  too  might  have  temperate  regions 
stretching  to  the  poles. 


CHAPTER  VI 

MARTIAN   POLAR  EXPEDITIONS 

"OOLAR  expeditions  exert  an  extreme  attraction  on 
certain  minds,  perhaps  because  they  combine  the 
maximum  of  hardship  with  the  minimum  of  head- 
way. Inconclusiveness  certainly  enables  them  to  be 
constantly  renewed,  without  loss  either  of  purpose  or 
prestige.  The  fact  that  the  pole  has  never  been  trod 
by  man  constitutes  the  lodestone  to  such  undertakings ; 
and  that  it  continues  to  defy  him  only  whets  his  en- 
deavor the  more.  Except  for  the  demonstration  of  the 
polar  drift-current  conceived  of  and  then  verified  by 
Nansen,  very  little  has  been  added  by  them  to  our 
knowledge  of  the  globe.  Nor  is  there  specific  reason  to 
suppose  that  what  they  might  add  would  be  particularly 
vital.  Nothing  out  of  the  way  is  suspected  of  the  pole 
beyond  the  simple  fact  of  being  so  positioned.  Yet 
for  their  patent  inconclusion  they  continue  to  be  sent 
in  sublime  superiority  to  failure. 

Martian  polar  expeditions,  as  undertaken  by  the 
astronomer,  are  the  antipodes  of  these  pleasingly  peril- 
ous excursions  in  three  important  regards,  which  if 
less  appealing  to  the  gallery  commend  themselves  to  the 

54 


CHAP,  vi        MARTIAN   POLAK  EXPEDITIONS  55 

philosopher.  They  involve  comparatively  little  hard- 
ship ;  they  have  accomplished  what  they  set  out  to  do  ; 
and  the  knowledge  they  have  gleaned  has  proved  funda- 
mental to  an  understanding  of  the  present  physical 
condition  of  the  planet. 

The  antithesis  in  pole-pursuing  between  the  two 
planets  manifests  itself  at  the  threshold  of  the  inquiry, 
in  the  relative  feasibility  with  which  the  phenomena 
on  Mars  may  be  scanned.  For,  curiously  enough,  in- 
stead of  being  the  pole  and  its  surrounding  paleo- 
crystic  ice  which  remains  hidden  on  Mars,  it  is  rather  the 
extreme  extent  of  its  extension  and  the  lowest  latitu- 
dinal deposit  of  frost  which  lies  shrouded  in  mystery. 
The  difficulty  there  is  not  to  see  the  pole  but  to  see  in 
winter  the  regions  from  which  our  own  expeditions  set 
out.  And  this  because  the  poles  are  well  displayed 
to  us  at  times  which  are  neither  few  nor  very  far  be- 
tween ;  while  favorable  occasions  for  marking  the  edge 
of  the  caps  when  at  their  greatest  have  neither  proved 
so  numerous  nor  so  favorable.  The  tilt  of  the  planet's 
axis  when  conveniently  placed  for  human  observation 
has  been  the  cause  of  the  one  drawback ;  the  planet's 
meteorological  condition  in  those  latitudes  at  that 
season  the  reason  for  the  other. 

What  knowledge  we  have  of  the  size  of  the  caps  in 
degrees  upon  the  surface  of  the  planet  at  this  their 
extreme  equatorward  extension  has  been  given  in  the 


56 


MARS  AND   ITS   CANALS 


last  chapter.  Their  aspect  at  the  time  together  with 
what  that  aspect  betokens  was  not  there  touched  upon. 
With  it,  therefore,  and  the  peculiarities  it  presents  to 
view  we  shall  begin  our  account  of  the  caps'  annual 
history. 

When  first  the  hemisphere,  the  pole  of  which  has  for 
~"rialf  a  Martian  year  been  turned  away  from  the  sun, 
begins  to  emerge  from  its  long  hibernation,  the  snow- 
cap  which  covers  it  down  even  to  temperate  regions 
presents  an  undelimited  expanse  of  white,  the  edges 
of  which  merge  indistinguishably  into  the  groundwork 
color  of  the  regions  round  about.  Of  a  dull  opaque 
hue  along  its  border,  its  contour  is  not  sharp  but  fades 
off  in  a  fleecy  fringe  without  hard  and  fast  line  of  de- 
marcation. Such  notably  was  the  aspect  of  the  north 
temperate  zone  in  1896  when,  tilted  as  it  then  was  away 
from  us  into  a  mere  northern 
horizon  of  the  planet's  limb, 
it  showed  prior  to  the  definite 
recognition  of  the  north  polar 
cap  in  August  of  that  year, 
and  such  too  was  the  look  of 
the  disk's  southern  edge  both 
before  and  after  the  first  cer- 

South  Polar  Cap  in  winter. 

tain  detection  of  the  south- 
ern cap  in  1903  and  1905.  Each  was  then  in  the  depth 
of  winter.  For  in  Martian  chronology  the  season  cor- 


CHAP,  vi        MARTIAN   POLAR  EXPEDITIONS  57 

responded  in  each  at  the  time  to  what  we  know  in  our 
northern  hemisphere  as  the  latter  part  of  February 
and  the  early  part  of  March  and  the  appearance  of  the 
planet's  surface  in  both  was  not  unlike  what  we  know 
at  the  same  season  in  latitude  45°.  Indeed,  there  is 
reason  to  suppose  bad  weather  there  then  and  the 
extreme  fringe,  from  the  pale  tint  it  exhibited,  to  have 
been  cloud  rather  than  snow. 

It  is  quite  in  keeping  with  what  we  know  on  earth 
or  can  conceive  of  elsewhere  that  such  aspect  should 
characterize  the  cap  at  or  near  the  attainment  of  its 
greatest  development.  Whether  it  were  not  yet  quite 
arrived  at  this  turning-point  of  its  career  or  had  but 
slightly  passed  it  a  vagueness  of  outline  would  in  either 
event  proclaim  the  fact.  For  were  the  frost  still  de- 
positing, the  cap's  edge  would  show  indefinite ;  and  on 
the  other  hand  had  it  just  begun  to  melt,  evaporation 
would  give  it  an  undefined  edge  before  the  melting 
water  had  gathered  in  sufficient  quantities  to  be  itself 
noticeable. 

Its  behavior  subsequent  to  recognition  bore  out  the 
inference  from  its  aspect  when  it  first  appeared.  While 
for  many  days  prior  to  its  coming  unmistakably  into 
view  it  was  impossible  to  say  whether  what  was  seen 
of  the  southern  cap  in  1903  and  1905  was  cloud  or 
snow;  so  even  after  it  had  definitely  disclosed  itself  it 
continued  to  play  at  odds  with  the  observer.  Showing 


58  MARS  AND  ITS  CANALS  CHAP,  vi 

sharp  at  the  edges  one  day  it  would  appear  but  hazily 
defined  the  next,  thus  clearly  demonstrating  itself  to  be 
at  the  then  unstable  acme  of  its  spread.  Such  a  state 
of  things  we  are  only  too  familiar  with  in  our  own 
March  weather  when  after  days  of  sunshine  that  have 
melted  off  the  winter's  white  and  fringed  it  with  rivulets 
and  awakening  grass,  a  snow-storm  falling  upon  it  pow- 
ders the  ground  again  that  was  beginning  to  be  bare 
and  at  one  stroke  extends  the  domain  of  the  snow  while 
mystifying  the  actual  limits  it  may  be  said  to  occupy. 
The  same  condition  of  things,  then,  is  not  unknown  on 
Mars,  and  to  fix  the  precise  date  of  so  wavering  a  phe- 
nomenon is  not  so  much  matter  of  difficult  observation 
as  of  physical  impossibility. 

Nor  is  the  southern  cap,  at  this  the  height  of  its 
winter  expansion,  confined  strictly  to  its  own  proper 
limits.  Faint  extensions,  now  so  connected  with  its 
main  body  as  to  form  part  and  parcel  of  it,  now  so  de- 
tached and  dull  of  tint  as  to  make  the  observer  doubt- 
ful of  the  exact  relationship,  are  generally  to  be  seen 
attendant  on  it.  Hellas  in  winter  is  much  given  to  such 
questionable  garb,  and  has  in  consequence  been  mis- 
taken by  more  than  one  observer  for  the  cap  itself, 
appearing  as  it  does  well  upon  the  southern  limb  and 
being  often  the  only  region  to  show  white.  Indeed, 
frost-bound  as  it  then  is,  to  consider  it  the  polar  cap, 
though  possibly  geographically  incorrect,  may  cli- 


CHAP,  vi        MARTIAN   POLAR   EXPEDITIONS  59 

matologically  be  sustainable.  Its  northern  extremity 
extends  down  to  latitude  30  °,  a  pretty  low  latitude 
for  frost.  Still  such  equator- 
ward  extension  is  not  with- 
out corroborating  parallel. 
In  1903,  at  what  was  in 
Martian  dates  April  26,  the 
whole  of  the  region  south  of 
the  Solis  Lacus  and  the 
Nectar  showed  white,  with  a 
whiteness  which  may  as  well  Hellas  in  winter" 

have  been  hoarfrost  as  cloud.     Now,  the  Nectar  runs 
east  and  west  in  latitude    28°.     So  that  in  this  in- 
stance, too,  it  is  possible  that 
arctic  conditions  knocked  at 
\  \      the  very  doors  of  the  tropics. 


A  i 


\  \  Encroachment  of  the  sort  is 
equivalent  to  snow  in  Cairo 
and  permanent  snow  at  that ; 
not  an  occasional  snow  flurry, 
but  something  to  linger  on 

White  south  of  Nectar  and  fae   groun(J   an(i    gtay   visible 

Solis  Lacus. 

sixty  millions  of  miles  away. 

Knowledge  of  either  cap  in  this  the  midwinter  of  its 
year  has  been  a  matter  of  the  most  recent  oppositions 
of  the  planet.  Up  to  within  the  last  few  years  our 
acquaintance  with  either  cap  was  chiefly  confined  to  the 


60  MARS  AND   ITS   CANALS  CHAP,  vi 

months,  —  one  might  almost  say  the  weeks,  —  imme- 
diately surrounding  the  summer  solstice  of  its  respec- 
tive hemisphere.  The  behavior  of  the  caps  during  the 
rest  of  their  career  was  largely  unknown  to  us,  from 
the  very  disadvantageous  positions  they  occupied  at  the 
times  the  planet  was  nearest  to  the  earth.  Beginning 
with  1894,  however,  our  knowledge  of  both  has  been 
much  extended,  by  a  proportionate  extension  of  the 
period  covered  by  the  observations.  It  used  to  be 
thought  impracticable  to  observe  the  planet  far  on 
either  side  of  opposition;  now  it  is  observed  from  as 
much  as  four  months  before  that  event  to  the  same 
period  after  it.  The  result  is  a  systematic  series  of  ob- 
servations which  in  many  ways  has  given  unexpected 
insight  into  Martian  conditions.  One  of  the  benefits 
secured  has  been  the  lengthening  of  the  period  of  study 
of  the  cap's  career,  a  pushing  of  inquiry  farther  back 
into  its  spring  history  and  a  longer  lingering  with  it 
in  its  autumnal  rebuilding.  Yet  up  to  the  very  last 
opposition  a  gap  in  its  chronology  still  remained  be- 
tween February  25  and  April  1.  The  opposition  of 
1905  has  bridged  this  hiatus  and  brought  us  down  to 
the  latter  date,  at  which  the  melting  of  the  cap  begins 
Jn  earnest. 

From  this  point,  April  1  on,  we  have  abundant  evi- 
dence of  the  cap's  behavior.  Its  career  now  for  some 
time  is  one  long  chronicle  of  contraction.  Like  Bal- 


CHAP,  vi        MARTIAN  POLAR  EXPEDITIONS  61 

zac's  Peau  de  Chagrin  it  simply  shrinks,  giving  out  of  its 
virtue  in  the  process.  The  cap  proceeds  to  dwindle 
almost  under  the  observer's  eye  till,  from  an  enor- 
mous white  counterpane  spread  over  all  the  polar  and 
a  large  part  of  the  temperate  zone,  its  area  contracts 
to  but  the  veriest  nightcap  of  what  it  was  before. 
From  seventy  degrees  across  it  becomes  sixty,  then 
fifty,  then  forty,  till  by  the  middle  of  the  Martian 
May  it  has  become  not  more  than  thirty  degrees  in 
diameter.  During  this  time,  from  the  moment  the 
melting  began  in  good  earnest,  the  retreating  white 
is  girdled  by  a  dark  band,  of  a  blue  tint,  which 
keeps  pace  with  the  edge  of  the  cap,  shrinking  as  it 
shrinks,  and  diminishing  in  width  as  the  volume  of 
the  melting  decreases. 

After  the  melting  has  been  for  some  time  under  way 
and  the  cap  has  become  permanently  bordered  by  its 
dark  blue  band  a  peculiar  phenomenon  makes  its 
appearance  in  the  cap  itself.  This  is  its  fission  into  one 
or  more  parts.  The  process  begins  by  the  appearance 
of  dark  rifts  which,  starting  in  from  the  cap's  exterior, 
penetrate  into  its  heart  until  at  last  they  cleave  it  in 
"Two.  Rifts  have  been  seen  by  several  observers  and  in 
both  caps;  and  what  is  most  suggestive  they  always 
appear  in  the  same  places,  year  after  year.  Sometimes 
oppositions  elapse  between  their  several  detections 
for  they  are  not  the  least  difficult  of  detail ;  but  when 


62  MARS  AND   ITS   CANALS  CHAP,  vi 

they  are  caught,  they  prove  to  lie  just  where  they  did 
before. 

The  permanency  in  place  of  the  rifts,  a  characteristic 
true  of  them  all,  shows  them  to  be  of  local  habit.  Thus 
the  rift  of  1884  and  1897  reappeared  again  to  another 
observer  in  the  same  position  in  1901.  They  are,  there- 
fore, features  of,  or  directly  dependent  on,  the  surface 
of  the  planet.  But  it  will  not  do  from  this  fact  to  infer 
that  they  are  expressive  of  depressions  there.  The 
«  evidence  is  conclusive  that  great  irregularities  of  sur- 
~L_face_do  not  exist  on  Mars.  As  we  shall  see  when  we 
come  to  consider  the  orology  of  the  planet  it  is  certain 
that  elevations  there  of  over  two  or  three  thousand  feet 
in^altitude  are  absent.  Differences  of  temperature,  able 
to  explain  a  melting  of  the  ice  in  one  locality  coinci- 
dentally  with  its  retention  in  an  adjacent  one,  must  in 
consequence  be  unknown.  And  this  much  more  con- 
clusively than  at  first  appears,  for  the  reason  that  the 
smaller  the  planet's  mass  the  less  rapidly  does  its 
blanket  of  air  thin  out  in  ascent  above  the  surface. 
This  is  in  consequence  of  the  greater  pull  the  larger 
body  exerts  and  the  greater  density  it  imparts  to  a  com- 
pressible gas  like  our  atmosphere.  Gravity  acts  like 
any  force  producing  pressure  and  by  it  the  envelope  of 
air  is  squeezed  into  a  smaller  compass.  But  as  this  is 
done  throughout  the  atmospheric  layer  it  means  a 
more  rapid  rarefaction  as  one  leaves  the  body.  The 


CHAP,  vi        MARTIAN  POLAE   EXPEDITIONS  63 

action  is  such  that  the  height  necessary  to  reach  an 
analogic  density  varies  inversely  as  the  gravity  of  the 
mass.  In  consequence  of  this,  to  compass  a  rela- 
tive thermometric  fall  for  which  a  moderate  difference 
of  elevation  would  suffice  on  Earth,  an  immoderate 
one  must  be  made  on  Mars.  For  gravity  there  being 
but  three  eighths  what  it  is  here,  eight  thirds  the  rise 
must  be  made  to  attain  a  proportionate  lowering  of 
temperature.  This  fact  renders  the  above  argument 
against  elevation  and  depression  being  the  cause  of 
the  phenomenon  three  times  as  cogent  as  it  otherwise 
would  be. 

V"ith  so  gradual  a  gradient  in  barometric  pressure 
there  and  so  low  a  set  of  contour  lines,  altitude  must  be 
a  negligible  factor  in  Martian  surface  meteorologic 
phenomena.  Both  density  and  temperature  can  be  but 
little  affected  by  such  cause,. and  we  must  search  else- 
where for  explanation  of  what  surface  peculiarities 
we  detect. 

Meanwhile  the  rifts  themselves,  from  being  lines 
which  penetrate  the  cap  from  its  periphery  in  toward 
its  centre,  end  by  traversing  it  in  its  entirety  and  sepa- 
rating portions  which,  becoming  outlying  subsidiary 
patches,  themselves  proceed  to  dwindle  and  eventually 
disappear.  The  rifts  usually  take  their  rise  from  such 
broader  parts  of  the  cap-encircling  blue  belt -as  make 
beads  upon  that  cordon  and  are  clearly  spots  where  the 


64 


MARS  AND   ITS   CANALS 


product  of  the  melting  of  the  cap  is  either  specially 
collected,  or  produces  its  most  visible  effect. 

So  far  the  description  might  apply  with  substantial 
accuracy  to  either  cap!  Yet  the  conduct  of  the  two  is 
in  some  ways  diverse  and  begins  to  accentuate  itself 
from  this  point  on. 

From  the  time  that  the  north  polar  cap  reaches  a 
diameter  of  about  twenty-five  degrees,  a  singular  change 
steals  over  it.  From  having  been  up  to  then  of  a  well- 
defined  outline  it  now  proceeds  to  grow  hazy  and 
indistinct  all  along  its  edge.  This  change  in  its  char- 
acter at  the  same  period  of  its  career  has  been  quite 
noticeable  at  each  of  the  three  last  oppositions,  so  that 
small  doubt  remains  that  the 
metamorphosis  is  a  regularly 
recurrent  one  in  the  history 
of  the  cap.  Coincident  with 
the  obliteration  of  its  con- 
tour, its  dimensions  seem- 
ingly enlarge.  It  is  as  if  a 
hood  had  been  drawn  over 
the  cap  of  a  dull  white  dif- 
ferent from  the  dazzling  brilliance  of  the  cap  itself 
and  covering  more  ground.  Such  is  probably  what 
occurs ;  with  vapor  for  veil.  The  excessive  melting  of 
the  cap  produces  an  extensive  evaporation  which  then 
in  part  condenses  to  be  deposited  afresh,  in  part  re- 


Northern  Cap  hooded  with  vapor. 


CHAP,  vi        MAKTIAN   POLAR   EXPEDITIONS  65 

mains  as  a  covering,  shutting  off  from  our  view  the 
outlines  of  the  cap  itself.  It  would  seem  that  at  this 
time  the  cap  melts  faster  than  the  air  can  carry  it 
off.  A  sort  of  steaming  appears  to  be  going  on,  taking 
place  in  situ.  For  it  clearly  is  not  wafted  away. 
The  time  of  its  coming  too  is  significant.  For  the 
season  is  May  15,  the  height  of  time  for  a  spring  haze 
to  set  in.  Then  later  it  dissipates  with  the  same  quiet 
indefiniteness  with  which  it  gathered. 

It  is  some  time  in  Martian  June  before  the  spring 
haze  clears  away,  and  when  it  does  go,  only  a  tiny 
polar  cap  stands  revealed  be- 
neath it,  from  six  to  eight 
degrees  across,  or  from  a 
tenth  to  a  fifteenth  of  what 
it  was  when  it  passed  into 
its  curious  spring  chrysalis. 
The  date  of  emergence  va- 
ries. In  1903  it  occurred 

early,     the     haze     not      being  Northern  Cap  unmasked. 

marked  after  June  3,  though  recurring  again  at  inter- 
vals for  a  day  or  so.  In  1905  it  was  later;  percep- 
tibly thin  after  June  21  it  did  not  certainly  clear 
away  till  June  9  and  came  back  again  on  July  16  and 
possibly  on  the  25th. 

These  vicissitudes  of  aspect  give  us  glimpses  into  a 
sweet    unreasonableness    in    Martian    weather    which 


66  MARS   AND  ITS   CANALS  CHAP,  vi 

makes  it  seem  more  akin  to  our  own.  And  this  on  two 
counts,  diurnal  and  annual.  From  day  to  day  at- 
mospheric conditions  shift  for  purely  local  cause; 
while,  furthermore,  successive  Martian  years  are  not 
alike.  In  some  the  season  is  early;  in  others  late. 
So  that  Mars  is  no  more  exempt  than  are  we  from  the 
wantonness  of  weather. 

Clearly  disclosed  thus  reduced  to  its  smallest  possible 
terms  it  remains  for  some  months  of  our  days,  for  six 
weeks  of  its  own.  During  that  period  it  continues  prac- 
tically unchanged,  neither  increasing  nor  decreasing 
significantly  in  size,  nor  altering  notably  in  aspect. 
Measures  of  the  drawings  of  it  then  make  it  from  five 
to  eight  degrees  across  and  it  is  possible  that  it  really 
fluctuates  between  narrow  limits,  though  its  clear-cut 
outline  at  all  times  renders  the  variation  difficult  to 
explain.  We  are  not  so  near  it  as  we  could  wish; 
for  on  these  occasions  even  at  their  best  it  is  over  two 
hundred  times  as  distant  as  the  moon  and  the  greatest 
magnification  possible  still  leaves  it  a  hundred  thou- 
sand miles  away. 

To  the  south  polar  cap  a  somewhat  similar  history 
attaches,  but  with  a  difference.  In  its  case  no  such 
regularly  recurrent  spring  haze  has  yet  been  noted. 
The  melting  of  this  cap  would  seem  to  be  of  a  more 
orderly  nature  than  its  fellow  and  not  to  outdo  what 
can  conveniently  be  carried  off. 


CHAP,  v!        MARTIAN   POLAE  EXPEDITIONS  67 

That  an  excess  of  evaporation  should  not  take  place 
is  the  more  peculiar  from  the  fact  that  at  its  maximum 
it  is  the  larger  of  the  two  and  therefore  has  the  greater 
quantity  of  matter  to  get  rid  of.  Its  summer,  also, 
is  shorter  than  the  arctic  one,  so  that  it  has  the  less 
time  to  dispose  of  its  accumulations.  The  only  other 
respect  in  which  it  seems  to  be  differently  circum- 
stanced from  its  antipodes  is  in  the  character  of  its 
surroundings.  About  it  are  large  blue-green  areas 
which  with  intermissions  stretch  down  in  places  to 
within  less  than  ten  degrees  of  the  equator;  whereas 
the  other  pole  is  continuously  encircled  for  long  dis- 
tances by  practically  uninterrupted  ochre.  The  char- 
acter of  the  environment  seems  thus  the  only  thing  that 
can  account  for  the  difference  in  behavior  and  this 
proves  the  more  plausible  when  we  come  to  consider 
what  those  two  classes  of  regions  respectively  repre- 
sent. 

In  other  ways  as  well  the  southern  cap  is  the  more 
self-contained.  The  rifts,  indeed,  break  it  up  into 
separate  portions  and  these  in  part  remain  as  outlying 
detachments  of  the  main  body,  as  was  notably  the 
case  in  1877  and  in  1894,  but  they  hardly  have  the 
permanency  and  importance  of  those  similarly  formed 
about  the  arctic  pole.  Nothing  antarctic  for  instance 
compares  with  the  subsidiary  patch  of  the  north 
polar  regions  lying  in  longitude  206°,  which  both 


68  MARS   AND  ITS   CANALS  CHAP,  vi 

in  Schiaparelli's  time,  and  during  the  late  oppo- 
sitions as  well  was  almost  as  fixed  a  feature  of  the 
arctic  zone  as  the  cap  proper.  Not  quite  so  constant, 
however,  and  not  so  solid-looking  a  landmark  is  this 
patch  for  all  its  extent,  which  nearly  equals  the  area 
of  the  more  legitimate  portion.  It  bears  on  its  face  a 
more  pallid  complexion  as  if  it  were  thinner,  and  this 
is  borne  out  by  the  fact  that  it  occasionally  disappears, 
an  event  which  so  far  at  least  has  never  befallen  the 
northern  cap  itself. 

Less  constant  the  southern  one  is  to  its  own  minimum 
than  the  northern.  In  some  seasons,  in  most  in  fact, 
it  reaches  like  the  other  a  more  or  less  definite  limit 
of  diminution  which  it  does  not  pass.  But  this  is  not 
always  the  case.  In  1894  it  disappeared  entirely  at 
the  height  of  its  midsummer.  The  season  was  probably 
unusually  hot  then  in  the  southern  hemisphere  of  Mars. 

In  position  the  caps  have  something  to  say  about 
physiographic  conditions.  Both  caps  at  their  minima 
are  then  irregular  and  the.  centre  of  the  south  one  is 
markedly  eccentric  to  the  areographic  pole.  It  lies 
some  six  degrees  north  along  the  thirtieth  meridian. 
The  northern  one  is  also  probably  eccentric,  but  much 
less  so,  with  a  divergence  not  much  exceeding  a  degree 
and  of  doubtful  orientation.  Not  only  are  both  caps 
not  upon  their  respective  poles  but  they  are  not  oppo- 
site each  other,  the  one  lying  in  longitude  30°,  the  other 


CHAP,  vi       MARTIAN   POLAR  EXPEDITIONS  69 

in  290°.  This  speaks,  of  course,  for  local  action.  In 
some  wise  this  must  depend  on  the  configuration  of  the 
surface,  yet  so  far  as  markings  go  there  is  nothing  to 
show  what  the  dependence  is. 

The  ec centring  of  the  caps  is  paralleled  by  the  like 
state  of  things  on  earth.  The  pole  of  cold  does  not 
coincide  in  either  hemisphere  with  the  geographic  pole. 
On  the  earth  its  position  is  largely  determined  by  the 
distribution  of  the  land-masses.  Continents  are  not 
such  equalizers  of  heat  as  oceans  because  of  their  con- 
ductivity on  the  one  hand  and  their  immobility  on  the 
other.  In  winter  they  part  with  their  heat  more  quickly 
and  convection  currents  cannot  supply  the  loss.  This 
accounting  for  thermal  pole  eccentricity  is  inapplicable 
to  Mars  because  of  the  absence  there  of  bodies  of  water. 
And  it  is  significant  that  the  degree  the  earthly  poles 
of  cold  are  out  much  exceeds  what  is  the  case  on  Mars. 
Possibly  areas  of  vegetation  there  replace  to  some  effect 
areas  of  water.  It  is  certainly  in  favor  of  this  view  that 
the  arctic  regions  there  are  more  desert  than  the  ant- 
arctic and  that  the  north  pole  of  cold  occupies  more 
squarely  the  geographic  pole. 

Not  till  1903  did  the  actual  starting  again  of  either 
cap  chance  to  be  seen.  Nor  was  this,  indeed,  a  matter 
of  hazard  but  of  persistent  inquiry  by  observation 
prolonged  after  the  planet  had  got  so  far  away  that  its 
scanning  had  hitherto  been  discontinued.  Such  search 


70 


MARS   AND   ITS   CANALS 


beyond  the  customary  limits  of  observation  was  essen- 
tial to  success,  because  of  the  relation  of  the  axial  tilt 
to  the  position  of  the  planet  in  its  orbit.  At  an  oppo- 
sition well  placed  for  nearness,  the  tilt  is  such  as  largely 
to  hide  the  pole  and  to  present  the  polar  regions  too 
obliquely  to  view  for  effective  scanning.  This  is  true 
both  of  the  arctic  and  the  antarctic  regions  in  turn. 
For  the  Martian  axis  being  inclined  somewhat  as  our 
own  is  to  the  plane  of  the  planet's  orbit,  we  at  times 
see  well  and  at  times  but  poorly  the  arctic  or  antarctic 
zones. 

The  cap,  the  starting  to  form  of  which  was  thus 
caught,  was  the  arctic  one;  the  date  128  days  after 
the  northern  summer  solstice,  or  thereabouts,  for  as  is 
perhaps  natural  the  advent  of  the  phenomenon  partook 
of  the  wavelike  advance  of  such  things  familiar  on 
earth,  an  advance  succeeded 
by  a  recession  and  then  fol- 
lowed by  another  advance. 
So  much  is  proof  of  local 
weather  there  as  here.  Hoar- 
frost was  successively  de- 
posited and  then  melted  off. 
What  is  significant,  the 
deposition  of  the  frost  took 
place  simultaneously  over  large  areas.  The  very  first 
patch  of  it,  in  about  longitude  320°,  extended  at  one 


Deposition  of  frost. 


CHAP,  vi       MARTIAN   POLAK  EXPEDITIONS  71 

stroke  down  to  latitude  55°.  For  it  actually  crossed 
the  Pierius  somewhat  to  the  south.  A  second  patch' 
stretched  to  the  east  of  the  cap.  Two  wings  these  made 
to  the  kernel  of  cap  itself.  Through  the  wings  could 
be  marked  the  line  of  the  canal :  the  Pierius  upon  the 
one  side,  the  Enipeus  upon  the  other.  Such  visi- 
bility of  the  canals  through  the  white  stretches  proved 
the  white  not  to  be  due  to  cloud  suspended  between  us 
and  them,  but  a  surface  deposit  which  found  no  lodg- 
ment upon  the  canals  themselves.  The  same  avoid- 
ance of  dark  markings  was  evidenced  by  the  showing 
of  the  dark  rim  round  the  cap's  kernel.  Now,  if  the 
deposit  were  indeed  hoarfrost,  this  failure  to  find  per- 
manent foothold  on  the  dark  markings  is  what  we  should 
expect  to  witness.  For  whether  they  were  vegetation 
or  water,  equally  in  either  case  the  frost  would  melt 
from  them  first.  Probably  they  were  both  vegetal, 
though  some  doubt  might  exist  about  the  latter,  the 
band  around  the  kernel.  It  was  then  August  20  in 
that  hemisphere. 

Such  deposition  over  great  stretches  of  country  is 
perhaps  not  so  surprising  as  it  appears  at  first  sight 
when  seen  from  without  in  its  totality.  After  all, 
something  not  unlike  it  occurs  in  our  snow-storms  when 
hundreds  of  square  miles  are  whitened  at  once.  Fur- 
thermore, with  an  atmosphere  as  thin  as  Mars  seems 
to  possess  the  temperature  must  be  perilously  near  the 


72  MAES  AND  ITS  CANALS  CHAP,  vi 

freezing-point  in  the  arctic  and  subarctic  regions  at 
the  close  of  summer. 

Steadily,  with  intermissions,  the  white  sheet  increased 
until  even  the  dark  border  to  the  cap  became  obliterate, 
the  kernel  showing  at  first  through  the  veil  like  the 
ghost  of  what  it  had  been,  and  then  ceasing  to  be  visible 
at  all,  its  delimitations  being  buried  under  deeper  and 
deeper  depositions  of  frost. 

The  perennial  portion  of  the  cap  was  thus  merged 
in  the  new-fallen  snow.  This  marked  the  on-coming  of 
the  arctic  winter  in  full  force 
and  happened  even  before 
the  polar  sun  had  wholly  set. 
For  the  pole  did  not  enter 
into  the  shadow  till  two  of 
our  months  later,  the  au- 
tumnal equinox  occurring 
183  days  after  the  summer 
First  northern  snow.  solstice  or  55  days  after  the 

first  fall  of  frost.  Then  the  pole  passed  into  its  star- 
strewn  arctic  night,  a  polar  night  of  twice  the  duration 
of  our  own  and  the  circumpolar  regions  entered  upon 
their  long  hibernation  of  ten  of  our  months. 


CHAPTER  VII 

WHITE    SPOTS 

TN  addition  to  the  polar  caps  proper  and  to  the 
subsidiary  polar  patches  that  often  in  late  sum- 
mer flank  them  round  about,  other  white  spots  may 
from  time  to  time  be  seen  upon  the  disk.  In  appear- 
ance these  differ  in  no  respect,  so  far  as  observed, 
from  the  arctic  subsidiary  snow-fields.  Of  the  same 
pure  argent,  they  sparkle  on  occasion  in  like  manner 
with  the  sheen  of  ice.  Equally  with  the  polar  caps 
they  remain  permanent  in  place  during  the  period  of 
their  visibility  and  are  themselves  long-lived.  Though 
by  no  means  perpetual  their  duration  is  reckoned  by 
weeks  and  even  months,  and  they  recur  with  more  or 
less  persistency  at  successive  Martian  years.  That, 
when  seen,  they  show  in  particular  positions  apparently 
unaffected  by  diurnal  change  precludes  their  being 
clouds,  and  this  fact  taken  in  connection  with  the 
character  of  their  habitat  is  the  puzzling  point  about 
them.  For  they  affect  chiefly  the  north  tropic  belt. 
They,  or  at  least  their  nuclei,  are  small,  about  two  or 
three  degrees  in  diameter,  and  are  not  particularly 
easy  of  detection  as  a  rule,  though  certain  larger  ones 

73 


74  MARS   AND  ITS   CANALS  CHAP,  vn 

are  at  times  conspicuous.  Chromatic,  rather  than 
formal,  definition  is  necessary  to  their  bringing  out,  as 
is  witnessed  by  the  superb  colors  the  disk  presents  at 
the  times  when  they  are  best  seen.  It  is  then  that 
Mars  puts  on  the  look  of  a  fire-opal. 

The  first  such  spot  to  be  noticed  was  one  which 
Schiaparelli  detected  in  1879,  at  the  second  opposition 
in  which  he  studied  the  planet.  He  called  it  the  Nix 
Olympica,  showing  that  he  recognized  in  it  a  cousin- 
ship  to  the  polar  snows.  Yet  it  lay  in  latitude  20° 
north,  longitude l  131°,  in  the  midst  of  the  ochre 
stretches  of  that  part  of  the  disk.  It  was  a  small 
roundish  white  speck  of  not  more  than  two  thirds  the 
diameter  of  the  polar  cap.  Reseen  by  him  in  1881, 
it  failed  to  appear  at  subsequent  oppositions  and  was 
not  caught  again  until  1888.  Then  once  more  it  van- 
ished, not  to  be  detected  anew  till  many  years  after 
at  Flagstaff,  coming  out  rather  surprisingly  in  1903. 
It  showed,  however,  in  the  same  place  as  before; 
so  that  its  position  but  not  its  existence  is  permanent. 

A  similar  but  smaller  patch  was  apparent  to  Schia- 
parelli at  the  same  opposition  of  1879.  This  one  which 

1  Martian  longitudes  are  now  reckoned  from  the  Fastigium  Aryn, 
the  mythologic  cupola  of  the  world,  a  spot  easy  of  recognition  be- 
cause making  the  tongue  in  the  jaws  of  the  Sabaeus  Sinus.  It  further 
commends  itself  because  of  lying  within  a  degree  of  the  equator.  The 
longitudes  are  reckoned  thence  westward  all  the  way  round,  or 
to  360°. 


WHITE   SPOTS 


75 


he  styled  the  Nix  Atlantica  lay  between  the  Thoth 
and  the  Syrtis  Major.  It  was  about  half  the  size  of  the 
Nix  Olympica  and  has  never  since  been  seen,  though 
it  should  have  been  had  it  continued  to  be  what  it  then 
was. 

On  the  other  hand,  phenomena  of  the  sort  undetected 
of  Schiaparelli  have  been  remarked  at  Flagstaff.  On 
May  18,  1901,  I  was  sud- 
denly struck  by  the  singular 
whiteness  of  the  southeast 
corner  of  Elysium  where 
that  region  bordered  the 
Trivium.  Elysium  has  a 
way  of  being  bright  but  not 
with  such  startling  intensity 
as  this  spot  presented  nor 
in  so  restricted  an  area  as  was  here  the  case.  The 
spot  was  so  much  whiter  than  anything  I  had  ever 
previously  seen  outside  the  polar  caps  that  it  arrested 
my  attention  at  once.  And  this  the  more  that  I  had 
observed  this  same  part  of  the  planet  the  day  before 
and  perceived  nothing  out  of  the  ordinary.  Once 
detected,  however,  the  spot  continued  visible.  The 
next  day  it  was  there  with  equal  conspicuousness,  and 
now  thrust  an  arm  across  the  Cerberus,  entirely  ob- 
literating the  canal  for  the  space  of  several  degrees. 
In  this  salience  it  remained  day  after  day  till  the 


White  in  Elysium. 


76  MARS  AND  ITS  CANALS  CHAP.  VH 

region  passed  from  sight,  to  reappear  with  it  six 
weeks  later  when  the  region  again  rounded  into  view. 
The  hour  of  the  Martian  day  seemed  to  make  no 
difference  in  its  visibility.  It  was  seen  from  early 
morning  till  Martian  afternoon,  as  late  as  the  phase 
permitted.  Clearly  there  was  nothing  diurnal  about 
its  revealing,  and  it  lasted  for  at  least  three  months 
and  a  half,  until  the  planet  got  so  far  away  that 
observations  were  discontinued. 

It  was  to  all  appearances  and  intents  snow.  But 
now  comes  the  singular  fact  about  it.  It  lay  within 
ten  degrees  of  the  equator  and  showed  from  the  end  of 
June  to  the  latter  part  of  August.  To  our  ideas  there 
could  be  no  more  inopportune  place  or  time  for  such 
an  exhibition.  For  it  cannot  have  been  due  to  a  snow- 
capped peak,  as  we  know  for  certain  that  there  are  no 
mountains  in  this,  or  in  any  other,  part  of  the  planet. 
Besides,  it  had  not  appeared  in  previous  Martian 
years ;  which  it  infallibly  would  have  done  had  it  been 
a  peak.  Indeed,  it  baffles  explanation  beyond  any 
Martian  phenomenon  known  to  me.  It  seems  directly 
to  contradict  every  other  detail  presented  by  the 
disk. 

The  phenomenon  is  thus  unique  in  kind;  it  is  not, 
however,  unique  as  a  specimen  of  its  kind.  The  eastern 
coast  of  Aeria  where  that  region  borders  the  Syrtis 
Major  is  prone  to  a  brilliance  of  the  same  sort.  It  is 


CHAP,  vii  WHITE   SPOTS  77 

a  narrow  belt  of  country  that  shows  thus,  nothing  but 
the  coastline  itself,  but  this  for  a  considerable  distance 
stretching  several  hundred  miles  in  length.  It  has 
stood  out  saliently  bright  now  at  every  opposition 
which  I  have  observed,  beginning  with  1894.  Some- 
times it  has  been  described  in  the  notes  as  bright 
simply,  sometimes  as  white,  and  once,  in  1901,  as  glis- 
tening at  one  point  like  ice.  Yet  when  upon  the  termi- 
nator it  has  never  stood  forth  as  a  mountain  range 
should  have  done  to  declare  its  character. 

It  has  been  evident  regardless  apparently  of  the  Mar- 
tian season.  In  1894  it  was  bright  from  October  25 
to  January  16  (Martian  chronology) ;  in  1896,  from 
December  22  to  January  7 ;  in  1901,  from  July  13  to 
the  15th;  in  1903,  at  about  the  same  date  and  so  in 
1905.  It  was  whitest  during  the  latter  oppositions, 
showing  that  the  effect  is  most  marked  in  its  mid- 
summer. All  of  the  above  instances  of  extra-polar 
white  have  been  located  within  the  tropics.  Examples 
of  the  same  thing,  however,  occur  in  the  north  tem- 
perate zone.  Tempe,  a  region  just  to  the  west  of  the 
Mare  Acidalium,  is  exceedingly  given  to  showing  a 
small  white  spot  close  upon  the  Mare's  border  in 
latitude  50°  north.  This  spot,  too,  on  occasion 
glitters  as  it  were  with  ice.  It  is  also  at  times  very 
small.  So  that  whereas  much  of  Tempe  is  by  nature 
bright  but  a  small  kernel  of  it  is  dazzling. 


78 


MARS   AND   ITS   CANALS 


White  in  the  Pons  Hectoris. 


The  list  might  be  easily  extended  from  the  record 
book.  Thus  on  March  1  and  2,  1903,  the  disk  showed 
speckled  with  minute  white  spots,  one  in  Arcadia  in 
latitude  41°  north,  one  in 
Tharsis  near  the  equator,  a 
third  just  north  of  the 
Phoenix  Lucus  in  10°  south, 
and  a  fourth,  the  Nix 
Olympica,  and  on  April  11, 
a  glittering  pin-point  starred 
like  a  diamond  the  centre  of 
the  Pons  Hectoris.  On  both 
these  occasions  the  Martian  season  was  summer; 
July  9  for  the  latter,  June  21  for  the  former  date. 
As  one  approaches  the  north  pole  spots  of  like  char- 
acter become  more  numerous.  Especially  are  such 
visible  north  of  the  Mare  Acidalium  in  the  arctic  region 
thereabout,  from  63°  to  75°  north. 
-—From  so  widespread  a  set  of  instances  the  only  ex- 
planation which  seems  to  fit  the  phenomena  is  that  the 
mean  temperature  of  Mars  is  low,  not  very  much  above 
freezing,  and  that  whatever  causes  a  local  fall  in  the 
temperature  results  in  hoar-frost.  Such  an  explanation 
"accords  well  with  the  distance  of  the  planet  from  the 
sun  and  the  thinness  of  its  atmosphere.  At  the  same 
time  it  shows  that  the  mean  temperature  over  the 
greater  part  of  the  planet  the  greater  part  of  the  time 


CHAP,  vii  WHITE   SPOTS  79 

is  above  the  freezing-point  and  that  consequently 
it  is  no  bar  to  vegetation  of  a  suitable  sort. 

the  hoar-frost  should  be  found  even  at  the 
equator  may  perhaps  be  due  to  the  very  thinness  of 
the  air-covering  of  Mars,  which  would  tend  to  make 
the  actual  insolation  more  of  a  factor  than  it  is  with  us, 
and  by  the  great  length  of  the  Martian  seasons.  In 
midsummer  the  greatest  insolation  occurs  in  the  arctic 
and  temperate,  not  in  the  tropic  regions ;  on  the  other 
hand,  an  atmosphere  tends  to  accumulate  heat  for  the 
tropics.  With  us  the  latter  factor  is  prepotent;  it 
would  be  less  effective  on  Mars.  Then  again  the  double 
duration" of  summer  would  tend  to  emphasize  insolation 
as  the  important  factor  in  the  matter.  But  it  is 
possible  that  greater  deposition  plays  a  part  in  the 
matter.  On  earth  the  rainfall  is  greatest  near  the 
equator  and  something  of  the  sort  may  be  true  of  the 
zones  of  moisture  on  Mars.  That  the  most  striking  spots 
-"lire  found  to  the  west  of  large  dark  areas  may  in  this 
connection  have  a  meaning  inasmuch  as,  such  regions 
being  vegetation-covered,  the  air  over  them  is  probably 
more  moisture-laden. 

~"~0ne  point  about  the  position  of  the  spots  is  of 
moment:  they  have  all  been  found  in  the  northern 
hemisphere  or  within  ten  degrees  of  it  in  the  southern 
equatorial  region.  This  seems  at  first  a  question  of 
hemispheres ;  but  when  we  consider  that  the  light  areas 


80  MARS  AND   ITS   CANALS  CHAP,  vn 

of  the  surface  are  chiefly  in  the  boreal  hemisphere  and  in 
the  south  tropic  belt,  we  perceive  that  it  may  be  rather 
the  character  of  the  surface  there  than  the  particular 
hemisphere  in  the  abstract  that  is  decisive  in  the  matter. 
Nevertheless,  the  austral  hemisphere  is  the  hemisphere 
of  extremes,  possessing  a  shorter,  hotter  summer  and 
a  longer,  colder  winter  than  its  antipodes.  This  would 
not  favor  sporadic  small  depositions  of  frost  in  summer 
so  much  as  would  a  climate  of  a  more  mean  tempera- 
ture. 

>m  the  relative  lack  of  atmospheric  covering  over 
the  planet  we  should  expect  the  nights  to  prove  de- 
cidedly cool,  while  the  days  were  fairly  warm.  Of  this 
we  have  perhaps  evidence  in  a  singular  aspect  shown 
by  the  Mare  Acidalium  in  June,  1903.  The  account 
of  it  in  the  Annals  reads  thus :  "On  May  22  an  inter- 
esting and  curious  phenomenon  presented  itself.  On 
that  day,  so  soon  as  the  Mare  Acidalium  had  well 
rounded  the  terminator  on  to  the  disk,  at  X352°,  the 
whole  of  its  central  part  showed  white,  the  edges  of 
the  marking  alone  remaining  as  a  shell  to  this  brilliant 
core.  So  striking  was  the  effect  that  beside  appear- 
ing in  the  drawing  it  found  echo  in  the  notes.  The 
next  day  no  mention  is  made  of  it,  and  a  drawing 
made  under  X20°  shows  the  Mare  as  usual  and  the 
bright  spot  in  Tempe  in  its  customary  place.  Neither 
was  anything  of  the  sort  noticed  on  the  24th  and  25th. 


CHAP,  vii  WHITE   SPOTS  81 

But  on  the  26th,  the  day  of  the  projection  (upon  the 
terminator),  the  effect  of  the  23d  reappeared,  the  longi- 
tude of  the  centre  being  332°.  Fortunately  on  that 
day  a  further  drawing  was  secured  which  enabled  its 
subsequent  behavior  to  be  followed.  Made  three  hours 
later  than  the  other,  the  longitude  of  the  centre  being 
13°,  this  drawing  shows  the  Mare  well  on  the  disk,  its 
whole  area  as  dark  as  usual  and  with  Tempe  bright  to 
the  right  of  it  toward  the  terminator.  The  terminator 
in  question  was  the  sunrise  one,  and  we  are  offered  two 
suppositions  in  explanation  of  the  phenomenon :  either 
the  white  was  due  to  a  morning  deposition  of  hoar-frost 
which  dissipated  as  the  sun  got  up,  or  obliquity  ren- 
dered some  superficial  deposit  visible  which  more  verti- 
cal vision  hid.  That  the  former  inference  is  the  more 
probable  seems  hinted  at  by  the  simultaneous  appear- 
ance from  the  19th  to  the  26th  of  other  areas  of  white 
between  the  Mare  and  the  pole.  May  26  was  88  days 
after  the  northern  summer  solstice,  and  corresponded 
to  July  31  on  the  earth."  Annals,  Volume  III,  §  564. 
In  this  connection  mention  may  pertinently  be  made 
of  Schiaparelli's  repeated  observation  of  regions  that 
whiten  with  obliquity,  a  proclivity  to  which  he  par- 
ticularly noticed  Hellas  and  certain  'islands'  in  the 
Mare  Erythraeum  to  be  prone.  Here  as  with  the  Mare 
Acidalium  we  certainly  seem  to  be  envisaging  cases  of 
matutinal  frost  melted  by  midday  under  the  sun's  rays. 


CHAPTER  VIII 

CLIMATE    AND   WEATHER 

TN  gazing  at  the  successive  phases  presented  by  the 
polar  caps  as  their  annual  history  unrolls  itself  to 
view,  beginning  with  vast  white  cloaks  that  in  winter 
hide  so  effectively  the  planet's  shoulders,  to  little  round 
knobs  that  in  summer  sit  like  guardsmen's  caps  more  or 
less  askew  upon  the  poles,  the  bodily  eye  sees  only  the 
glisten  of  far-off  snow.  The  mind's  eye,  however, 
perceives  something  more :  the  conviction  they  carry 
of  the  presence  of  an  atmosphere  surrounding  the 
planet.  Elusive  as  water  vapor  is  to  sight  for  its 
transparency  and  to  spectroscopic  determination  for 
its  earthly  omnipresence,  recognition  of  its  existence 
elsewhere  by  deduction  raises  such  reasoning  at  once 
to  a  more  conspicuous  plane  than  it  might  otherwise 
assume.  Especially  is  this  true  where  the  deduction  is 
itself  conclusive,  as  is  here  the  case.  For  it  depends 
on  phenomena  not  its  own,  but  which  are  in  their  turn 
dependent  on  it.  We  are  not  even  beholden  to  any 
knowledge  of  the  substance  composing  the  caps  for  the 
fundamental  inference  that  an  atmosphere  surrounds 
them.  Whatever  that  substance  were,  the  fact  that 


CHAP,  vin  CLIMATE   AND  WEATHER  83 

the  caps  dissipate  and  reform  shows  us  with  absolute 
certainty  that  they  pass  into  the  gaseous  state,  to  be 
later  solidified  afresh.  This  gas  constitutes  of  itself 
an  atmosphere;  while  another  phenomenon,  to  wit, 
IJneir  blue  girdles  as  they  melt,  affirming  their  substance 
to  be  snow  and  ice,  enables  us  to  precise  the  fact  that 
this  gas  is  water  vapor. 

From  such  premise  given  us  by  the  polar  caps  we  are 
able  to  infer  much  more  by  the  help  of  the  kinetic 
theory  of  gases.  But  the  speed  of  parting  by  a 
planet  with  its  gases  is  conditioned  by  the  mean 
speed  of  each  gas.  Water  vapor  will,  therefore,  go 
before  nitrogen,  oxygen  or  carbonic  acid  gas.  If, 
then,  we  find  it  present  over  the  surface  of  a  planet 
we  are  assured  of  the  possibility  that  the  other  three 
may  be  there  too,  and  from  the  similarity  of  matter 
in  space  strong  reason  to  suspect  that  they  actually 
are. 

Corroborative  evidence  of  the  accuracy  of  the  deduc- 
tion as  to  the  presence  of  a  Martian  air  is  shown  in 
several  other  ways ;  in  the  existence  of  clouds  to  begin 
with.  Rare  as  they  are,  these  certainly  float  at  times 
""over  parts  of  the  planet,  although  it  is  doubtful  whether 
they  can  then  be  seen.  Fortunately  for  assurance  we 
have  other  ways  of  ascertaining  their  presence  than 
that  of  obscuration.  Nor  is  it  of  account  to  the  argu- 
ment that  they  should  be  few  and  far  between,  as  they 


84  MAES   AND   ITS   CANALS  CHAP,  vm 

unquestionably  are.  One  single  instance  of  such  medi- 
umistic  support  is  enough  to  support  the  theory  of  a 
medium;  and  that  instance  has  been  more  than  once 
observed. 

Direct  evidence  of  atmosphere  is  further  forthcoming 
in  the  limb-light.  This  phenomenon  might  be  de- 
scribed as  a  brilliant  obscuration.  It  is  a  circlet  of 
illumination  that  swamps  the  features  as  they  near  the 
full  edge  of  the  disk,  the  limb  of  the  planet  as  it  is 
called.  Obliteration  of  the  sort  is  evident,  more  or 
less  markedly,  at  all  times,  and  is  not  due  to  foreshort- 
ening, as  the  broadest  areas  are  affected.  The  fading 
out  of  the  detail  at  the  limb  suggests  nothing  so  much 
as  a  veil  drawn  between  us  and  it,  lighter  in  tint  than 
what  it  covers.  Such  a  veil  can  be  none  other  than 
air  or  the  haze  and  cloud  that  air  supports.  From  its 
effect,  impartial  in  place  and  partial  in  character, 
cloud  is  inadmissible  as  a  cause  and  we  are  left  with  air 
charged  with  dust  or  vapor  in  explanation.  Obscura- 
tion due  to  it  should  prove  most  dense  at  the  limb, 
since  there  the  eye  has  to  penetrate  a  greater  depth  of 
it ;  just  as  on  the  earth  our  own  air  gives  azure  dimness 
to  the  distance  in  deepened  tinting  as  the  mountains 
lie  remote. 

Another  bit  of  evidence  lies  in  the  apparent  detec- 
tion of  a  twilight  arc.  In  1894  measures  made  of  the 
polar  and  equatorial  diameters  of  the  planet  showed 


CHAP,  vin  CLIMATE  AND   WEATHER  85 

certain  systematic  residuals  left  after  all  known  correc- 
tions had  been  applied.  The  only  thing  which  would 
account  for  them  was  the  supposition  that  a  twilight 
arc  had  been  unconsciously  seen  and  as  unconsciously 
measured.  In  delicate  quantities  of  the  sort  too  great 
reliance  cannot  be  put,  but  if  the  residuals  be  not  refer- 
able to  other  cause  they  give  us  not  only  further  evi- 
dence of  an  atmosphere,  but  at  the  same  time  our  only 
hint  of  that  atmosphere's  extent.  From  them  it 
would  seem  that  the  air  must  be  rare,  not  more  than 
about  four  inches  of  barometric  pressure,  as  we  reckon 
it,  and  probably  less;  a  thin,  high  air  more  rarefied 
than  prevails  upon  our  highest  mountain  tops. 

Corroborative  of  this  is  the  aspect  of  the  planet. 
From  the  general  look  of  the  disk  a  scant  covering 
of  air  is  inferable.  For  one  of  the  striking  things 
about  the  planet's  features  is  their  patent  exposure  to 
our  sight.  Except  in  the  winter  time  of  its  hemisphere 
or  in  the  spring  after  the  greatest  melting  of  the  polar 
cap,  nothing  seems  to  stand  in  our  way  of  an  uninter- 
rupted view  of  the  surface,  whether  in  the  arctic,  tem- 
perate, or  tropic  zones.  From  the  openness  of  its 
expression,  however,  too  much  case  should  not  be 
made  as  we  really  know  but  little  of  how  an  atmosphere- 
enshrouded  planet  would  look.  We  find  no  difficulty 
in  seeing  objects  a  hundred  miles  away  across  the  sur- 
face of  the  earth  and  yet  the  thickness  of  the  air  strata 


86  MARS  AND  ITS   CANALS  CHAP,  vm 

in  such  horizontal  traversing  is  many  fold  what  it  is 
when  we  look  directly  up.  It  is  also  out  of  all  propor- 
tion laden  with  dust  and  smoke.  In  the  purer  regions 
of  the  earth,  a  clear  air  imposes  but  little  bar  to  sight, 
and  conjures  up  far  things  startlingly  distinct. 

Nevertheless,  every  evidence  points  to  a  thin  air 
upon  Mars :  a  priori  reasoning,  indirect  deduction  and 
direct  sight.  Now,  from  a  thinness  of  atmosphere  it 
would  follow,  other  things  equal,  that  the  climate  was 
cold.  About  this  there  has  been  much  question,  but 
less  of  answering  reply.  From  the  distance  of  the 
planet  from  the  sun  it  is  certain  less  heat  is  received 
by  it  than  falls  upon  the  earth  in  something  like  the 
ratio  of  one  to  two.  But  that  the  amount  effective 
is  as  the  amount  received  is  far  from  sure.  The  avail- 
able heat  is  much  affected  by  the  manner  of  its  recep- 
tion. A  blanket  of  air  acts  like  the  glass  of  a  conser- 
vatory, letting  the  light  rays  in,  but  hindering  the  heat 
rays  out.  The  light  rays  falling  on  the  ground  or  the 
air  are  transformed  into  heat  rays  that,  finding  the  re- 
turn journey  less  easy,  are  consequently  trapped.  All 
substances  are  thus  calorifiers,  but  water  vapor  is 
many  times  more  potent  than  ordinary  air  to  heat- 
ensnaring.  A  humid  air  has  a  hothouse  tang  to  it  most 
perceptible.  Now,  what  the  relative  percentage  of 
water  vapor  in  the  Martian  atmosphere  may  be  we 
do  not  know. 


CHAP,  vin  CLIMATE   AND  WEATHER  87 

The  thinness  of  the  Martian  air  has  caused  it  to  be 
likened  to  that  upon  our  highest  mountain  peaks 
which  are  in  large  part  covered  with  perpetual  snow. 
But  the  comparison  is  not  well  founded.  A  peak  differs 
materially  from  a  plateau  in  the  countenance  it  gives 
to  the  heat  falling  upon  it.  On  a  plateau  each  warmed 
acre  of  ground  helps  the  retention  of  heat  by  its  neigh- 
bor ;  while  in  addition  to  being  destitute  of  side  support 
the  higher  winds  generated  about  an  isolated  peak  blow 
its  own  caloric  away.  Still  less  does  any  analogy  hold 
between  the  two  when  the  plateau  is  a  world- wide  one. 

From  these  considerations  it  is  evident  glosses  are 
possible  upon  the  bald  idea  of  a  much  lower  temperature 
prevailing  on  the  Martian  surface  than  on  the  earth's. 
Doubtless  the  theoretic  cold  has  been  greatly  overdone. 
Reversely,  recent  observations  tend  to  lower  the  appa- 
rent temperature  disclosed  by  the  features  of  the  disk, 
and  between  the  rising  of  the  theoretic  and  the  falling 
of  the  observed  we  are  left  with  a  very  reasonable 
compromise  and  reconcilement  as  the  result. 
~The  various  look  and  behavior  of  the  surface  of  Mars 
point  to  a  mean  temperature  colder  than  that  of  the 
earth,  but  above  the  freezing-point  of  water;  for 
regions,  at  least,  outside  of  the  polar  caps  and  during 
all  but  the  winter  months.  Except  at  certain  special 
spots,  and  possibly  even  there,  frost  is  unknown  at  all 
times  within  the  tropics  and  except  in  winter  in  tern- 


88  MAES  AND  ITS   CANALS  CHAP,  vm 

perate  latitudes.  These  anomalous  localities,  men- 
tioned in  the  preceding  chapter,  may  be  said  to  be  the 
exceptions  that  prove  the  rule  of  general  non-glacia- 
tion.  For  if  they  be  snow,  they  stand  witness  to  its 
absence  elsewhere  upon  the  disk,  and  if  they  are  not, 
they  testify  the  more  emphatically  to  the  same  effect. 

As  between  different  parts  of  the  surface,  the  tilt 
of  the  Martian  axis  and  the  greater  length  of  the  Mar- 
tian seasons,  the  one  the  same  as,  the  other  the  double 
of,  our  own,  tend  to  an  accentuation  of  the  heat  in  the 
temperate  and  arctic  or  antarctic  zones.  The  greatest 
insolation  on  earth  is  not,  as  we  might  suppose,  at  the 
equator,  but  at  the  parallels  of  43. °5  north  and  south; 
even  the  poles  themselves  receiving  a  quarter  as  much 
heat  again  on  midsummer  day  as  ever  falls  to  the  lot  of 
the  line.  This  broad  physical  fact  is  equally  true  of 
Mars,  while  in  the  matter  of  consecutive  exposure  Mars 
in  summer  outdoes  the  earth.  For  the  longer  the  sea- 
sons, the  more  nearly  does  the  effective  heat  approach 
the  received  amount.  Thus  both  on  the  score  of  heat 
received  and  of  heat  husbanded  these  zones  must  be 
relatively  warm.  And  this  shows  itself  in  the  look  of 
the  surface.  In  summer  it  is  clearly  warmer  within 
the  polar  regions  than  is  the  case  on  earth,  to  judge  by 
the  effect.  In  winter  the  cold  is  doubtless  propor- 
tionately severe. 

For  the  diurnal  range  of  temperature  we  have  less 


CHAP,  vin  CLIMATE  AND  WEATHER  89 

data.  There  is  evidence  pointing  to  chilly  nights,  but 
it  is  meagre,  and  we  are  left  to  fall  back  on  the  cold  of 
our  deserts  at  night  for  analogic  condition  of  the  state 
of  things  over  the  Martian  desert  levels  after  the  sun 
goes  down. 

If  we  are  uncertain  of  the  precise  character  of  the 
'^Martian  climate,  we  know  on  the  other  hand  a  good  deal 
about  the  Martian  weather.  A  pleasing  absence  of  it 
over  much  of  the  planet  distinguishes  Martian  conditions 
from  our  own.  That  we  can  scan  the  surface  as  we  do 
without  practical  interruption  day  in  and  day  out 
proves  the  weather  over  it  to  be  permanently  fair.  In 
fact  a  clear  sky,  except  in  winter,  and  in  many  places 
even  then,  is  not  only  the  rule,  but  the  rule  almost 
without  exceptions.  In  the  early  days  of  Martian 
study  cases  of  obscuration  were  recorded  from  time 
to  time  by  observers,  in  which  portions  of  the  disk  were 
changed  or  hidden  as  if  clouds  were  veiling  them  from 
view.  More  modern  observations  fail  to  support  this 
deduction,  partly  by  absence  of  instances,  partly  by 
other  explanation  of  the  facts.  Certainly  the  recorded 
instances  are  very  rare.  Indeed,  occasions  of  the  sort 
must  to  any  Martians  be  events,  since  only  one  possible 
example  has  presented  itself  to  me  during  the  course 
of  my  observations,  extending  more  or  less  over  eleven 
years.  Even  in  this  case  there  was  no  obliteration, 
though  a  certain  whiteness  overspread  an  area  near 


90  MAES  AND  ITS  CANALS  CHAP,  vm 

the  equator  temporarily.  Position  seemed  to  point  to 
its  identity  with  a  cloud  which  made  its  appearance 
about  that  time  upon  the  terminator,  and  lasted  for 
some  thirty-six  hours.  The  cloud,  however,  showed 
evidence  of  being,  not  the  kind  with  which  we  are  fa- 
miliar, but  a  dust-storm,  in  keeping,  indeed,  with  the 
desert  region  (Chryse)  in  which  it  originated. 

With  the  exception  of  sporadic  disturbance  of  the  sort 
the  whole  surface  of  the  planet  outside  the  immediate 
vicinity  of  the  polar  caps  seems  free  from  cloud  or  mist 
and  to  lie  perpetually  unveiled  to  space.  In  the  neigh- 
borhood of  the  caps,  however,  and  especially  round 
about  their  edge,  a  very  distinct  pearly  appearance  is 
presented  during  the  months  at  which  the  cap  is  at  its 
maximum,  or  in  other  words,  in  the  depth  of  its  winter. 
Of  a  dull  white  hue  and  indefinite  contour  the  phenome- 
non suggests  cloud.  Where  it  lies  spread  no  markings 
are  visible;  an  absence  explicable  by  obscuration  due 
an  interposed  medium,  but  equally -well  by  seasonal 
non-existence  of  the  markings  themselves,  which  from 
the  general  behavior  of  these  markings  we  know  to  be 
to  some  extent  certainly  the  fact.  Of  the  regions 
where  the  effect  is  noticeable,  Hellas  is  the  most  strik- 
ing. So  conspicuously  white  during  the  winter  of  the 
southern  hemisphere  as  to  have  been  often  mistaken  for 
the  polar  cap,  its  ghost  shows  thus  almost  regularly  every 
Martian  year.  What  is  as  suggestive  as  it  is  striking, 


CHAP,  vin  CLIMATE  AND  WEATHER  91 

the  blanching  is  confined  to  the  solid  circle  constituting 
Hellas  and  does  not  extend  into  the  dark  regions  by 
which  it  is  circumscribed.  Hellas  is  as  'self-contained 
when  thus  powdered  as  when,  in  its  normal  ochre  or 
abnormal  red,  it  stretches  like  a  broad  buckler  across 
the  body  of  the  disk.  That  the  land  there  lies  at  a 
higher  level  than  its  surroundings  is  pretty  certain,  but 
that  the  difference  can  amount  to  enough  to  explain  its 
silveriness  as  ice  is  improbable.  In  latitude  Hellas  is 
distinctly  temperate,  lying  between  the  parallels  of  55° 
and  30° ;  but  on  Mars  this  is  no  warrant  of  a  like  climate. 
Again,  though  close  on  the  south  to  what  constitutes 
the  polar  cap,  it  does  not  strictly  form  part  of  that  cap, 
but  occupies  both  in  position  and  in  kind  a  something 
intermediary  between  the  frost-bound  regions  of  peri- 
odic snow  and  the  warmer  ones  of  perpetual  sunshine. 
It  seems  to  be  afflicted  with  the  winter  weather  of  the 
north  of  Europe,  and  to  owe  its  pearly  look  at  such  times 
to  the  same  cloud  canopy  that  then  distressingly  covers 
those  inclement  lands. 

Similar  in  behavior  to  it  is  the  long  chain  of  so- 
called  islands  that,  beginning  southwest  of  Thau- 
masia,  runs  thence  westward  even  to  the  eastern  edge 
of  Hellas.  These  belt  the  planet  in  a  west-northwesterly 
direction  by  a  strip  of  territory  from  ten  to  fifteen  de- 
grees wide,  the  medial  line  of  which  begins  at  55° 
south  and  ends  in  about  40°.  They  are  parted  from 


92  MARS   AND   ITS   CANALS  CHAP,  vm 

the  main  bright  areas  by  blue-green  'seas'  of  about  the 
same  width  as  themselves,  the  Mare  Sirenum,  the  Mare 
Cimmerium  and  Mare  Tyrrhenum.  These  'seas' 
the  white  that  covers  the  'islands'  never  crosses; 
though  the  continent,  as  we  may  call  it  for  convenience, 
descends  at  the  east  to  30°  south.  Since  the  'seas' 
are  not  seas,  the  cause  which  might  bound  the  snow, 
were  they  such,  cannot  be  the  cause  here.  Neverthe- 
less, they  have  an  effect  of  some  sort  on  the  isothermal 
lines  as  is  shown  not  only  by  latitudinal  comparison 
with  the  state  of  things  in  Hellas,  but  with  that  in 
Thaumasia  as  well.  For  30°  south  is  also  the  limit  ap- 
parently of  the  white  on  Thaumasia,  where  ochre  desert 
stretches  ten  degrees  farther  south  still ;  the  region  in 
its  southern  part  being  white-mantled,  in  its  northern 
part  not.  Here  again,  then,  the  ochre  areas  make 
exception  to  what  affects  the  blue-green  ones.  Clearly 
the  blue-green  regions  temper  the  action  of  what  gives 
them  wintry  cloak.  But  why  they  should  do  this  is 
not  easy  to  explain  on  any  supposition  terrestrial  or 
marine.  Bodies  of  water  tend  to  foster  the  formation 
of  clouds;  so,  less  markedly,  do  areas  of  vegetation. 
Neither  the  old  ideas,  then,  nor  the  new  lend  themselves 
in  explanation.  It  may  be  that  while  we  here  seem 
to  be  envisaging  cloud  we  are  in  reality  looking  at  hoar- 
frost. On  the  other  hand,  light  cloud  would  show  less, 
superposed  over  a  dark  background,  than  over  an  ochre 


CHAP,  vin  CLIMATE  AND   WEATHER  93 

one;  and  this,  the  simplest  of  all  explanations,  may  be 
the  true  one.  It  is  facts  like  these  that  intrigue  us  in 
the  study  of  the  Martian  surface  by  revealing  conditions 
which  render  offhand  analogy  with  the  earth  unsafe. 
Indeed,  we  are  more  sure  of  some  things  which  appear 
too  strange  to  be  true  than  of  others  so  simple  on  their 
face  as  to  enlist  belief.  Among  the  most  difficult 
and  perplexing  are  meteorological  problems  like  the 
above.  Here  we  can  only  say  provisionally  that  while 
cloud  best  answers  to  the  appearance,  frost  best  fits  the 
cause.  For  vegetation  might  melt  frost,  yet  not  dissi- 
pate cloud.  By  raising  our  conception  of  the  mean 
temperature  the  facts  can,  however,  be  reconciled  and 
this  is  probably  the  solution  of  the  difficulty  after  all. 
As  we  saw  in  the  annual  history  of  the  polar  caps  a 
dimness  somewhat  different  affects  the  northern  cap  in 
May  and  June.  After  the  melting  of  the  cap  is  well 
under  way  a  haziness  sets  in  along  its  edge  which  be- 
fuddles its  outline  and  effectually  hides  what  is  going 
on  within  it.  When  at  last  the  screen  clears  away  the 
cap  is  found  to  be  reduced  to  its  least  dimensions. 
Such  obstructing  sheet  looks  to  be  more  of  the  nature 
of  mist  caused  by  the  excessive  melting  of  the  cap. 
Unfortunately,  there  are  here  no  patches  of  blue-green 
to  test  a  possible  partiality  in  its  behavior  over  such 
tracts ;  nor  has  similar  action  ever  yet  been  remarked 
in  the  case  of  the  cap  of  the  southern  hemisphere. 


94  MARS   AND  ITS   CANALS  CHAP,  vm 

Regular  recurrence  at  the  appropriate  season  of  the 
planet's  year,  together  with  extensive  action  at  the 
time,  takes  this  springtide  mist  to  some  extent  out  of 
the  domain  of  weather  into  that  of  climate.  For  it 
prevails  all  round  the  cap  and  repeats  itself  in  place 
as  each  fresh  spring  comes  on.  At  least  it  has  done  so 
for  the  past  three  oppositions  at  which  it  has  been  pos- 
sible to  observe  well  the  arctic  zones.  It  is  thus  both 
general  in  its  application  and  fixed  in  its  behavior. 
Nevertheless,  it  betrays  something  of  the  fickleness 
which  characterizes  that  more  inconstant  thing: 
weather.  For  it  comes  and  goes,  one  thinks  for  good, 
only  to  find  it  there  again  some  days  later.  Not  less 
captious  is  the  meteorologic  action  shown  in  the  mak- 
ing of  the  new  polar  cap.  When  the  northern  one  starts 
to  form,  vast  areas  of  frost  are  deposited  in  a  single 
night.  These,  however,  are  not  permanent.  The 
ground  thus  covered  is  during  the  next  few  days  again 
partially  laid  bare.  Then  a  new  fall  occurs,  hiding  the 
surface  a  little  more  completely  than  before,  and  the 
lost  domain  is  more  than  regained.  By  such  wave- 
like  advance  and  recession  the  tide  of  frost  creeps  over 
and  submerges  the  arctic  regions  as  the  late  summer 
passes  into  the  autumn.  In  this  alternate  coming  and 
going  with  succeeding  days,  we  have  an  unsteadfast- 
ness  of  action  most  fittingly  paralleled  by  our  own 
weather.  It  would  seem  that  local  causes  there  as  here 


CHAP,  vin  CLIMATE  AND  WEATHER  95 

are  superposed  upon  the  orderly  progress  of  the  sea- 
sons and  though  at  the  on-coming  of  the  autumn  the 
cold  is  steadily  gathering  strength,  nevertheless  warm 
days  occur  now  and  then  to  stay  its  hand,  only  to  be 
succeeded  in  their  turn  by  frosts  more  biting  than  be- 
fore. Even  on  Mars  nothing  in  the  way  of  weather 
is  absolutely  predicable  but  impredicability. 


CHAPTER  IX 

MOUNTAINS   AND   CLOUD 

TN  all  ways  but  one  our  scrutiny  of  the  planet  is 
confined  to  such  view  as  we  might  get  of  it  from 
the  car  of  a  balloon  poised  above  it  in  space;  from 
which  disadvantage-point  we  should  see  the  surface 
only  as  a  map  spread  out  below  us,  a  matter  of  but 
two  dimensions.  The  exception  consists  in  the  obser- 
vation of  what  are  called  projections;  irregularities 
visible  when  the  disk  is  gibbous  upon  that  edge  of  the 
planet  where  the  light  fades  off.  Striking  phenomena 
in  themselves  they  are  of  particular  value  for  what  may 
be  deduced  from  them.  For  by  them  we  are  afforded 
our  only  opportunity  of  gaining  knowledge  of  the  sur- 
face other  than  in  plan  and  thus  of  determining  be- 
tween peak,  plateau,  or  plain  that  to  a  bird's-eye  view 
alike  lie  flattened  out  to  one  dead  level. 

It  might  at  first  be  thought  that  our  best  chance  of 
noting  any  elevations  or  depressions  of  the  Martian 
surface  lay  in  catching  that  surface  in  profile,  by  scan- 
ning the  bright  edge  of  it  which  stands  sharp-cut 
against  the  sky  arid  is  called  the  limb.  For  this  is 
practically  what  we  do  on  earth  when  we  mark  a 


CHAP,  ix  MOUNTAINS   AND   CLOUD  97 

mountain  against  the  horizon  and  measure  its  height 
by  triangulation.  Unfortunately  the  method  fails  in 
the  case  of  Mars  because  of  the  great  distance  we  are 
away.  Unless  the  planet  were  distinctly  more  gen- 
erously equipped  than  the  earth  in  the  matter  of 
mountains,  nothing  could  be  hoped  from  so  forthright 
an  envisaging.  So  relatively  insignificant  to  the  size 
of  its  globe  is  the  relief  of  the  earth's  surface  that  an 
orange  skin  would  seem  grossly  rough  by  comparison. 
The  same  proves  true  for  Mars.  With  the  greatest 
magnification  we  can  produce,  the  Martian  limb  still 
appears  perfectly  smooth. 

Luckily,  while  direct  vision  is  thus  impossible,  oblique 
illumination  enables  us  to  get  an  insight  into  the 
character  of  the  surface  we  had  otherwise  been 
denied.  When  mountains  or  valleys  chance  to  lie 
upon  the  boundary  of  light  and  darkness,  the  rim  of 
the  disk  known  as  the  terminator  in  contradistinction 
to  the  limb  where  the  surface  itself  comes  to  an  end, 
they  make  their  presence  evident  through  an  indirect 
species  of  magnification,  the  elongate  effect  of  oblique 
lighting.  With  a  practical  instance  of  it  every  one 
is  familiar  who  has  walked  by  night  along  a  road  im- 
perfectly starred  at  intervals  by  electric  lights.  Startled 
between  posts  by  what  seemed  deep  holes  and  high 
furrows  he  has  involuntarily  imitated  a  spavined  horse 
for  fear  of  stubbing  his  toes,  only  to  encounter  when 


98  MAES  AND   ITS   CANALS  CHAP,  ix 

his  foot  fell  a  surface  on  contact  surprisingly  smooth. 
The  slant  illumination  by  lengthening  the  shadows 
had  painfully  deceived  him  into  exaggerated  inference 
of  irregularity.  What  proves  disturbing  to  a  way- 
farer misguided  by  arc  lights  is  made  to  do  the 
eye  service  when  it  comes  to  planetary  interpreta- 
tion. On  the  boundary  of  light  and  shade,  those 
parts  of  the  surface  where  it  is  sunrise  or  sunset 
upon  the  planet,  the  sun's  rays  fall  so  athwartwise 
as  to  throw  enormous  shadows  from  quite  small  eleva- 
tions to  an  eye  so  placed  as  to  view  the  surface  with 
anything  approaching  perpendicularity.  A  mountain 
mass  there  will  thus  proclaim  itself  by  protracted  pro- 
file upon  the  plain  in  hundredfold  magnification.  Simi- 
larly a  peak  there  will  advertise  its  height  by  catching 
the  coming  or  holding  the  lingering  light  at  many  times 
the  distance  of  its  own  elevation  away  from  the  night 
side  of  the  planet.  Here,  if  anywhere,  then,  could 
mountains  be  expected  to  disclose  themselves,  and 
here,  when  existent,  they  have  as  a  matter  of  fact 
been  found. 

Our  own  moon  offers  us  the  first  and  easiest  example 
of  such  vicariously  visible  relief.  When  the  moon  is 
near  the  quarter,  and  for  three  or  four  days  on  either 
side  of  that,  a  keen  eye  can  usually  detect  one  or  more 
knobs,  like  warts,  projecting  from  its  terminator, 
easily  distinguished  from  the  limb  both  by  reason  of 


CHAP,  ix  MOUNTAINS   AND   CLOUD  99 

being  less  bright  and  of  being  bounded  by  a  semi-ellipse 
instead  of  a  semicircle.  If  a  telescope  or  even  an  opera- 
glass  be  substituted  for  the  eye,  it  is  possible  to  see 
what  causes  them;  the  knob  resolves  itself  into  the 
illuminated  rim  of  a  crater  separated  from  the  main 
body  of  the  visible  moon  by  the  seemingly  black  void  of 
space.  The  peak  has  caught  the  sunlight,  while  its 
foot  and  the  country  between  it  and  the  illuminated 
surface  still  lies  shrouded  in  shadow. 

From  measurement  of  the  distance  the  sun-tipped 
peak  seems  to  stand  aloof  from  the  line  where  the  plain 
itself  is  touched  by  the  light,  the  height  of  it  above  that 
plain  may  be  calculated.  In  this  way  have  been  found 
the  heights  of  the  mountains  of  the  moon.  Incidentally, 
brain  outstrips  brawn.  For  pinnacles  no  Lunarian 
could  scale,  both  for  their  precipitous  inaccessibility 
and  their  loftiness,  man  has  measured  without  so 
much  as  setting  foot  upon  their  globe.  At  each  lunar 
sunrise  and  again  at  lunar  sunset  these  old  crater  walls 
show  their  crescent  coronets  tipped  the  reverse  way; 
and  peaks  higher  than  the  Himalayas  make  gigantic 
gnomons  of  themselves  with  hands  outstretched  to  grasp 
the  plains. 

In  this  manner  a  lunar  peak  of  fifteen  thousand  feet 
shows  its  presence  to  the  unaided  eye.  With  so  much 
for  starting-point  we  can  calculate  how  low  an  eleva- 
tion could  similarly  be  made  out  on  Mars  under  a  like 


100  MARS   AND  ITS   CANALS  CHAP,  ix 

phase  illumination.  Now,  in  spheres  of  different  diame- 
ters the  distance  out  from  the  terminator  for  a  given 
height  is  as  the  square  root  of  the  diameter.  Mars  has 
about  twice  the  size  of  the  Moon.  In  consequence,  if 
we  saw  the  planet  at  the  same  distance  off  as  the  Moon, 
the  height  of  a  peak  upon  it  sufficient  to  cast  an  equal 
shadow  or  be  seen  at  an  equal  separation  from  the 
terminator  need  be  but  two  thirds  as  high.  To  see 
it  thus  equidistant  a  power  of  250  or  300  is  necessary, 
dependent  on  the  opposition.  Twice  this  power  may 
at  times  be  used,  and  by  the  same  reasoning  this 
would  reduce  the  height  sufficient  to  show  by  four 
or  to  something  like  2500  feet.  This,  then,  would  be 
the  theoretic  limit  of  the  visible,  a  limit  needing  to 
be  somewhat  increased  because  of  the  imperfection  of 
our  air. 

Having  found  thus  what  should  be  visible  on  Mars 
we  turn  now  to  see  what  is.  At  once  we  find  ourselves 
confronted  with  a  very  unlunar  state  of  things.  Com- 
mon upon  the  face  of  the  Moon,  excrescences  of  the 
terminator  are  rare  on  Mars.  The  first  ever  seen  was 
detected  by  a  visitor  at  the  Lick  Observatory  in  1888. 
Since  then  they  have  been  repeatedly  noticed  both  at 
the  Lick  and  elsewhere.  But  although  observers  are 
now  on  the  watch  for  them,  they  are  not  very  fre- 
quently chronicled  because  not  of  everyday  occurrence. 
Much  depends  upon  the  opposition;  some  approaches 


MOUNTAINS   AND   CLOUD 


101 


of  the  planet  proving  more  prolific  of  them  than  others. 
How  rare  they  are,  however,  may  be  gathered  from  the 
fact  that  the  last  three  oppositions  have  disclosed  but 
one  apiece. 

An  account  of  the  great  projection  of  May  25,  1903, 
will  give  an  idea  of  the  extent  and  interest  of  the  phe- 
nomenon and  will  serve  to  show  to  what  cause  we  must 
attribute  all  such  that  have  been  visible  on  Mars,  for 
the  behavior  of  this  one  was  typical  of  the  class. 

About  half  past  eight  o'clock  in  the  evening  of  May 
26,  1903,  Mr.  V.  M.  Slipher,  astronomer  at  Flagstaff, 
shortly  after  taking  over  the  telescope  then  directed 
upon  Mars,  suddenly  noticed  a  large  projection  about 
halfway  up  the  terminator 
of  the  planet.  He  at  once 
sent  word  of  the  fact  and 
the  observatory  staff  turned 
out  to  see  it,  for  a  projec- 
tion has  for  workers  on  Mars 
the  like  interest  that  a  new 
comet  possesses  for  astrono- 
mers generally.  In  this  case 
the  phenomenon  was  specially  potent  in  that  it  was 
the  first  to  be  detected  that  year.  Its  singularity  was 
amply  seconded  by  its  size.  For  it  was  very  large,  its 
extent  both  in  length  and  height  being  excessive. 
When  I  first  saw  it,  the  projection  consisted  of  an 


Projection  on  terminator. 


102  MARS  AND  ITS   CANALS  CHAP,  ix 

oval  patch  of  light,  a  little  to  the  north  of  the  centre 
of  the  phase  ellipse  lying  parallel  to  the  terminator 
but  parted  from  it  by  darkness  to  the  extent  of  half 
the  projection's  own  width.  It  made  thus  not  simply 
an  excrescence  but  a  detached  islet  of  light.  It  was 
easily  seen  by  all  those  present  and  was  carefully 
studied  from  that  time  on  by  Mr.  Slipher  and  me. 
Both  of  us  made  drawings  of  it  alternately  at  inter- 
vals, as  well  as  micrometer  measures  of  its  position. 

Next  to  its  great  size,  the  most  striking  feature  about 
it  was  its  color.  This,  instead  of  being  white  or  whitish, 
was  ochre  orange,  a  hue  closely  assimilated  to  the  tint 
of  the  subjacent  parts  of  the  disk,  which  was  the  region 
known  as  Chryse.  This  distinctive  complexion  it  kept 
throughout  the  period  of  its  apparition.  At  the  same 
time  Baltia,  a  region  to  the  north  of  it  and  synchro- 
nously visible  close  upon  the  terminator,  showed  whitish. 
The  seeing  was  good  enough  to  disclose  the  Phison  and 
Euphrates  double,  the  power  a  magnification  of  310 
and  the  aperture  the  full  aperture  of  the  24-inch 
objective. 

From  the  time  it  was  first  seen  the  detached  patch 
of  light  crept  in  toward  the  disk,  the  illuminated  body 
of  the  planet.  Four  minutes  after  I  noted  it  the  dark 
space  separating  it  from  the  nearest  point  of  the  termi- 
nator had  sensibly  lessened.  So  it  continued,  with 
some  fluctuations  intrinsic  to  the  atmospheric  dim- 


CHAP,  ix  MOUNTAINS   AND  CLOUD  103 

culties  of  observations  generally  and  to  the  smallness 
of  the  object  itself,  to  become  gradually  less  and  less 
salient.  It  lasted  for  about  forty  minutes  from  the 
moment  it  had  first  appeared  to  Mr.  Slipher  and  then 
passed  from  sight  to  leave  the  edge  of  the  planet  smooth 
and  commonplace  again. 

The  measures  made  on  it  showed  that  it  lay  when 
first  seen  in  longitude  39°.7,  latitude  18°.5  north,  and 
that  its  highest  point  stood  seventeen  miles  above  the 
surface  of  the  planet.  It  was  three  hundred  miles 
long.  These  are  my  own  figures,  from  which  Mr. 
Slipher's  do  not  substantially  differ. 

The  return  of  the  part  of  the  planet  where  it  had  been 
seen  was  eagerly  awaited  the  night  after  by  both 
observers,  to  see  if  it  would  bring  the  projection  with  it. 
For  only  once  a  day  is  the  same  region  of  Mars  similarly 
presented.  But  in  order  not  to  miss  the  projection, 
should  it  be  ahead  of  time,  observations  were  begun 
before  it  was  due.  Shortly  after  they  were  started, 
there  appeared  higher  up  the  terminator  and  therefore 
farther  north  than  had  been  the  case  the  night  before, 
a  small  projection.  It  was  with  difficulty  made  out 
and  its  position  measured.  Without  careful  watching 
it  must  have  been  missed  altogether.  As  it  was,  it 
differed  in  every  respect  from  that  of  the  preceding 
day.  It  was  not  nearly  so  high,  not  nearly  so  large, 
and  lay  in  a  different  place  on  the  planet,  being  now 


104  MARS  AND  ITS   CANALS  CHAP,  ix 

in  longitude  31°.7,  latitude  25°.5.  Either  the  two, 
therefore,  were  totally  different  things  or  the  projec- 
tion had  moved  in  the  elapsed  interval  of  time  over 
seven  degrees  of  latitude  and  eight  degrees  of  longitude, 
a  distance  of  three  hundred  and  ninety  miles  in  twenty- 
four  hours.  Where  the  previous  projection  had  been 
nothing  showed.  On  the  following  night,  May  28,  no 
trace  of  anything  unusual  could  be  seen  anywhere. 

We  are  now  concerned  to  inquire  to  what  this  series 
of  appearances  could  have  been  due.  The  first  observ- 
ers of  projections  on  Mars  had  unhesitatingly  attrib- 
uted them  to  the  same  cause  that  produces  projections 
on  the  Moon,  to  wit,  mountains.  Such  they  were 
held  to  be  in  France  and  at  the  Lick.  This  view,  how- 
ever, was  in  1892  disputed  by  W.  H.  Pickering  who 
considered  them  to  be  not  mountains,  but  cloud.  And 
this  view  was  strongly  supported  by  A.  E.  Douglass 
in  a  discussion  of  a  large  number  of  them  observed  in 
1894  at  Flagstaff.  The  mountain  theory  of  their 
generation  was  finally  shown  to  be  untenable  and  their 
ascription  to  cloud  conclusively  proved  to  be  the  cor- 
rect solution  by  the  observations  of  a  remarkable 
one  made  in  December,  1900,  and  the  careful 
study  to  which  by  the  writer  they  were  subjected. 
— We  shall  now  explain  how  this  was  done  and  we  will 
begin  by  pointing  out  that  the  fact  that  only  a  single 
specimen  of  the  phenomenon  was  visible  at  each  of  the 


CHAP,  ix  MOUNTAINS  AND   CLOUD  105 

three  oppositions  of  1900,  1903,  and  1905  was  itself 
conclusive,  rightly  viewed,  of  their  non-mountainous 
character.  This  conclusion  follows  at  once  from  the 
isolateness  of  the  phenomenon.  For  a  mountain  cannot 
change  its  place.  Now,  the  shift  in  the  aspect  presented 
by  the  planet's  disk  from  one  night  to  the  next  is  not 
sufficient  to  alter  perceptibly  the  appearance  shown 
by  anything  upon  its  edge  on  the  two  occasions.  If, 
then,  a  peak  stood  out  upon  it  one  evening,  the  peak 
should  again  show  salient  when  the  region  reached  the 
same  position  upon  the  succeeding  night.  That  noth- 
ing then  was  seen  where  something  had  previously 
been  visible  proved  the  phenomenon  not  that  of  a 
mountain  peak,  since  what  produced  the  projection 
was  clearly  not  fixed  in  place  and  therefore  not  attached 
to  the  soil.  Now  the  only  other  thing  capable  of  catch- 
ing the  light  before  it  reached  the  surface  would  be 
something  suspended  in  the  air,  that  is,  a  cloud.  De- 
duction, therefore,  from  the  rarity  of  the  phenomenon 
alone  showed  that  the  projections  must  be  clouds. 

Their  behavior  in  detail  entirely  corroborates  this 
deduction  from  their  intermittence.  Such  was  shown 
by  the  action  of  the  projection  of  December  6, 1900, 
as  set  forth  in  a  paper  before  the  American  Philosophi- 
cal Society  and  such  again  by  that  of  the  one  of  May 
26,  1903,  as  we  shall  now  note.  To  begin  with,  we 
notice  that  the  projection  seen  on  May  26  was  not 


106  MARS   AND   ITS   CANALS  CHAP,  ix 

found  either  in  situ  or  in  size  on  May  27  and  had  wholly 
vanished  on  May,  28,  though  the  seeing  was  substan- 
tially the  same  if  not  better  on  the  two  nights  succeed- 
ing that  of  its  original  detection.  Hence  in  its  own 
instance  this  projection  proved  an  alibi  irreconcilable 
with  the  character  of  a  mountain  mass.  But  it  did 
more.  It  not  only  was  not  on  the  second  evening 
what  and  where  it  had  been  on  the  first,  but  the  remains 
of  it  visible  on  the  second  occasion  showed  clearly  that 
it  had  moved  in  the  meantime.  Furthermore  it  was 
disappearing  as  it  went,  for  it  was  very  much  smaller 
after  the  lapse  of  twenty-four  hours.  The  something 
that  caused  it  was  not  only  not  attached  to  the  soil, 
but  was  moving  and  dissipating  as  it  moved.  Only 
one  class  of  bodies  known  to  us  can  account  for  these 
metamorphoses  and  that  is:  cloud. 

But  what  kind  of  cloud  are  we  to  conceive  it  to  be  ? 
Our  ordinary  vapor  clouds  are  whitish  and  this  would 
be  still  more  their  color  could  they  be  looked  at  from 
above.  The  Martian  cloud  was  not  white  but  tawny, 
of  the  tint  exhibited  by  a  cloud  of  dust.  Nor  could 
this  color  have  very  well  been  lent  it  by  its  sunrise 
position,  for  other  places  equally  situated  to  be  tinged 
by  the  hues  of  that  time  of  day,  Baltia  to  wit,  showed 
distinctly  white.  So  that  we  must  suppose  it  to  be 
what  it  looked,  a  something  of  the  soil,  not  beholden 
to  atmospheric  tinting  for  its  hue;  a  vast  dust-cloud 


CHAP,  ix  MOUNTAINS  AND  CLOUD  107 

traveling   slowly  over  the  desert  and  settling   slowly 
again  to  the  ground. 

Precisely  the  same  general  course  of  drifting  disap- 
pearance was  taken  by  the  projection  of  December  7 
and  8,  1900.  And  this,  too,  stood  an  unique  appari- 
tion in  the  annals  of  its  opposition.  Clouds,  then,  and 
not  mountains  are  the  explanation  of  the  projections 
on  Mars,  differing  thus  completely  from  the  lunar  ones. 


CHAPTER   X 

THE    BLUE-GREEN    AREAS 

T~\ESCENDING  now  equator-wards  from  the  polar 
-*-^  regions,  and  their  in  part  paleocrystic,  in  part 
periodic,  coating  of  ice,  we  come  out  upon  the  general 
uncovered  expanse  of  the  planet  which  in  winter  com- 
prises relatively  less  surface  than  on  Earth,  but  in  sum- 
mer relatively  more.  Forty  degrees  and  eighty-six 
degrees  may  be  taken  as  the  mean  hiemal  and  sestival 
limits  respectively  of  the  snow  on  Mars;  forty-five 
and  seventy-five  as  those  of  the  Earth.  Whatever 
ground  is  thus  bared  of  superficial  covering  on  Mars  lies 
fully  exposed  to  view,  thanks  to  the  absence  of  obscur- 
ing cloud ;  and  it  is  at  once  evident  that  the  terrrane 
is  diversified,  patches  of  blue-green  alternating  with 
stretches  of  reddish  ochre.  Of  the  two  opaline  tints 
the  reddish  ochre  predominates,  fully  five  eighths  of  the 
disk  being  occupied  by  it. 

It  was  early  evident  in  the  study  of  the  surface 
of  Mars  that  its  ochreish  disk  was  not  spotless. 
Huyghens  in  1659  saw  the  Syrtis  Major.  From  this 
first  fruit  of  areography  dates,  indeed,  the  initial  recog- 
nition of  the  planet's  rotation;  for  on  noting  that 

108 


CHAP,  x  THE   BLUE-GREEN   AREAS  109 

the  marking  changed  its  place,  he  inferred  a  turning  of 
the  planet  upon  itself  in  about  twenty-four  hours.  Thir- 
teen years  later  he  observed  and  drew  it  again  and  this 
time  in  company  with  the  polar  cap.  Again,  after 
eleven  more  years,  he  depicted  it  for  the  third  time;  and 
now  so  changed  because  of  the  different  tilt  of  the  planet 
toward  the  earth  that  it  may  be  doubted  whether  Huy- 
ghens  himself  recognized  it  for  the  same.  But  that 
he  drew  it  correctly  a  globe  of  Mars  will  at  once  show. 
From  such  small  beginning  did  areography  progress 
to  the  perception  of  permanent  patches  of  a  sombre  hue 
distributed  more  or  less  irregularly  over  the  disk.  Im- 
pressing the  observers  simply  as  dark  at  first,  they  later 
came  to  be  recognized  as  possessing  color,  a  blue-green, 
which  contrasted  beautifully  with  the  reddish  ochre 
of  the  rest  of  the  surface.  Cassini,  Maraldi,  Bianchini, 
Herschel,  Schroeter,  all  saw  markings  which  they  re- 
produced. Finally,  with  Beer  and  Maedler,  came  the 
first  attempt  at  a  complete  geography.  In  and  out 
through  the  ochre  was  traced  the  blue;  commonly  in 
long  Mediterraneans  of  shade,  but  here  and  there  in 
isolated  Caspians  of  color.  With  our  modern  tele- 
scopic means  the  dark  patches  are  easily  visible,  the 
very  smallest  glass  sufficing  to  disclose  them.  When 
thus  shown  they  much  resemble  in  contour  the  dark 
patches  on  the  face  of  the  Moon  as  seen  with  the  naked 
eye.  Now  these  patches  were  early  taken  for  lunar 


110  MAES  AND  ITS   CANALS  CHAP,  x 

seas  and  received  names  in  keeping  with  the  conception ; 
as  the  Sea  of  Serenity,  the  Sea  of  Vapors,  and  so  forth. 
Following  the  recognition  of  a  like  appearance,  like 
appellatives  were  given  to  the  Martian  markings ;  and 
the  Mare  Sirenum,  or  Sea  of  the  Sirens,  the  Mare  Cim- 
merium,  and  others  sufficiently  proclaim  what  was 
thought  of  them  at  the  time  they  were  thus  baptized. 
Indeed,  if  a  general  similarity  be  any  warrant  for  a 
generic  name  they  were  not  at  the  time  ill-termed. 
For,  common  to  all  three  bodies,  the  Earth,  the  Moon, 
and  the  planet  Mars,  is  the  figuration  of  their  surfaces 
into  light  areas  and  dark.  In  the  Martian  disk,  as  in 
the  lunar  one,  we  seem  to  be  looking  at 'a  cartographic 
presentation  of  some  strange  geography  suspended  in 
the  sky;  the  first  generic  difference  between  the  two 
being  that  the  chart  is  done  in  chiaroscuro  for  the  Moon, 
in  color  for  Mars.  On  mundane  maps,  we  know  the 
dusky  washes  for  oceans;  so  on  the  Moon  it  was  only 
natural  to  consider  their  counterparts  as  maria;  and 
on  Mars  as  'seas.'  Nor  did  the  blue-green  hue  of  the 
Martian  ones  detract  from  the  resemblance. 

But  in  something  other  than  color  these  markings  are 
alike.  In  fact,  color  could  hardly  be  excuse  for  consider- 
ing the  lunar  maria  what  their  name  implies,  for  dis- 
tinctive tint  is  lacking  in  them,  even  to  the  naked  eye. 
It  was  in  form  that  the  likeness  lay.  Their  figures 
were  such  as  our  own  oceans  show;  and  allowing  for 


CHAP,  x  THE   BLUE-GREEN   AREAS  111 

a  sisterly  contrast  amid  a  sisterly  resemblance,  the 
lunar  maria  or  the  Martian  seas  might  well  have  been 
of  similar  origin  to  those  with  which  our  schoolboy 
study  of  atlases  had  made  us  familiar.  Thus  did  simi- 
larity in  look  suggest  similarity  in  origin,  and  intuitive 
recognition  clothe  its  objects  with  the  same  specific 
name. 

Considerable  assumption,  however,  underlay  the 
pleasing  simplicity  of  the  correlation  on  other  grounds, 
consequent  not  so  much  upon  any  lack  of  astronomic 
knowledge  as,  curiously,  upon  a  dearth  of  knowledge  of 
ourselves.  We  know  how  other  bodies  look  to  us,  but  we 
ignore  how  we  look  to  them.  It  is  not  so  easy  to  see 
ourselves  as  others  see  us ;  for  a  far  view  may  differ  from 
a  near  one,  and  a  matter  of  inclination  greatly  alter 
the  result.  Owing  both  to  distance  and  to  tilt  we 
lack  that  practical  acquaintance  with  the  aspect  of  our 
own  oceans  viewed  from  above,  necessary  to  definite 
predication  of  their  appearance  across  interplanetary 
space.  Our  usual  idea  is  that  seas  show  dark,  but  it  is 
also  quite  evident  that  under  some  circumstances  they 
appear  the  contrary.  It  all  depends  upon  the  position 
of  the  observer  and  upon  the  position  of  the  Sun.  Their 
usual  ultramarine  may  become  even  as  molten  brass 
from  indirect  reflection;  while  on  direct  mirroring, 
they  give  back  the  Sun  with  such  scarce  perceptible 
purloining  of  splendor  as  to  present  a  dazzling  sheen 


112  MARS   AND  ITS   CANALS  CHAP,  x 

not  to  be  gazed  upon  without  regret.  Canopied  by  a 
welkin  they  assume  its  leaden  hue,  while  at  the  same 
time,  their  shores,  less  impressionable  to  borrowed  light- 
ing, show  several  tints  darker  than  themselves.  Sur- 
faces so  sensitive  to  illumination  hardly  admit  of  more 
accusable  tint  than  a  chameleon.  Nevertheless,  we  are 
probably  justified  in  our  conviction  that  perpendicularly 
visaged,  they  would  on  the  whole  outdo  in  sombreness 
land  round  about  them,  and  so  be  evident  as  dusky 
patches  against  a  brighter  ground. 

One  phenomenon  we  might  with  some  confidence  look 
to  see  exhibited  by  them  were  they  oceans,  and  that  is 
the  reflected  image  of  the  Sun  visible  as  a  burnished 
glare  at  a  calculable  point.  Specular  reflection  of  the 
sort  was  early  suggested  in  the  case  of  Mars,  and  physical 
ephemerides  for  the  planet  registered  for  many  years 
the  precise  spot  where  the  starlike  image  should  be 
sought.  But  it  was  never  seen.  Yet  not  till  the  marine 
character  of  the  Martian  seas  had  been  otherwise  dis- 
proved was  the  futile  quest  for  it  abandoned.  Indeed, 
it  was  a  tacit  recognition  that  our  knowledge  had  ad- 
vanced when  this  column  in  the  ephemeris  was  allowed 
to  lapse. 

On  this  general  marine  ascription  doubt  was  first 
cast  in  the  case  of  the  Moon.  So  soon  as  the  telescope 
came  to  be  pointed  at  our  satellite,  it  was  evident  that 
the  darker  washes  were  not  water  surfaces  at  all,  but 


CHAP,  x  THE   BLUE-GREEN   AKEAS  113 

very  palpably  plains.  Long  low  ridges  of  elevation 
stood  out  upon  them  like  prairie  swells,  which  grew  in 
visible  relief  according  to  the  slanting  character  of  the 
illumination.  Cracks  or  rills,  too,  appeared  near  their 
edges  and  craters  showed  in  their  very  midst.  Pat- 
ently solid  they  betrayed  their  constitution  not  only 
by  diverse  topography  but  by  diversified  tint.  All 
manner  of  shades  of  neutral  tone  mottled  their  surface, 
from  seeming  porphyry  to  chalk.  Belief  perforce  de- 
parted when  the  telescope  thus  pricked  the  bubble, 
evaporating  as  the  water  itself  had  done  long  before. 

So  much  was  known  before  the  Mars'  markings  were 
named.  Nevertheless,  humanity,  true  to  its  instincts, 
promptly  proceeded  to  commit  again  the  same  mistake, 
and,  cheerfully  undeterred  by  the  exposure  of  its  errors 
in  the  case  of  the  Moon,  repeated  the  christening  in  the 
case  of  Mars.  So  sure  was  it  of  its  ground  that  what 
it  saw  was  not  ground,  that  though  the  particular  ap- 
pellatives of  the  several  seas  were  constantly  altered, 
rebaptisms,  while  changing  the  personal,  kept  the  generic 
name.  Dawes'  Ocean,  for  example,  later  became 
FOcean  Newton  and  later  still  the  Mare  Erythraeum, 
but  remained  set  down  as  much  a  sea  as  before.  About 
thirteen  years  ago,  however,  what  had  befallen  the 
seas  of  the  Moon,  befell  those  of  Mars:  the  loss  of 
their  character.  It  was  first  recognized  through  a 
similar  exposure ;  but  the  fact  was  led  up  to  and  might 


114  MAES  AND  ITS   CANALS  CHAP,  x 

have  been  realized  in  consequence  of  quite  a  different 
line  of  evidence.  The  initial  thing  to  cast  doubt  upon 
the  seas  being  what  they  seemed  to  be  was  the  detection 
of  change  in  their  aspect.  That  the  detection  was  not 
made  much  earlier  than  actually  happened  shows  how 
a  phenomenon  may  elude  observation  if  scrutiny  be 
not  persistent,  and  its  results  from  time  to  time  not 
carefully  compared.  Schiaparelli  was  the  one  who 
first  noticed  variation  in  the  look  of  the  seas,  and  the 
discovery  was  as  much  due  to  the  assiduity  with  which 
he  followed  the  planet  opposition  after  opposition  as  to 
the  keenness  with  which  he  scanned  it.  The  noting  of 
change  in  the  blue-green  areas  constituted,  in  fact,  one 
of  the  first  fruits  of  systematic  study  of  the  planet. 
Change  in  configuration,  that  is,  alteration  of  area,  pre- 
ceded in  recognition  alteration  of  tint.  Thus  the 
Syrtis  Major  showed  larger  to  him  in  1879  than  it  had 
in  1877.  This  was  natural ;  difference  of  degree  being 
a  more  delicate  matter  to  perceive  than  its  effect  upon 
extent.  From  change  of  area  his  perception  went  on 
to  change  of  tone.  In  his  own  words,  what  he  noticed 
was  this:  Memoria,  VI,  1888,  "No  less  certain  is  it 
that,  from  one  opposition  to  another,  one  notices  in  the 
seas,  very  remarkable  alterations  of  tone.  Thus  the 
regions  called  Mare  Cimmerium,  Mare  Sirenum,  and 
Solis  Lacus,  which  during  the  years  1877  to  1879  could 
be  numbered  among  the  most  sombre  on  the  planet, 


CHAP,  x  t  THE   BLUE-GREEN   AREAS  115 

during  the  succeeding  oppositions  became  less  and  less 
black,  and  in  1888  were  of  a  light  gray  hardly  sufficient 
to  render  them  visible  in  the  oblique  position  in  which 
all  three  found  themselves.  .  .  .  On  the  other  hand, 
at  the  very  same  moment,  the  Mare  Acidalium  and  the 
Lacus  Hyperboreus  showed  very  dark;  the  latter  in- 
deed appeared  nearly  black,  although  seen  as  tilted  as 
the  Syrtis  and  the  equatorial  bays.  The  condition  of  the 
regions  called  seas  is  therefore  not  constant :  so  much 
is  unquestionable.  Perhaps  the  change  produced  in 
them  has  to  do  with  the  season  of  the  planet's  year." 

Holding  as  he  did  the  then  prevailing  view  that  the 
blue-green  regions  were  bodies  of  water,  he  regarded 
those  of  intermediate  tint  as  vast  marshes  or  swamps, 
and  he  accounted  for  change  of  hue  in  them  as  due  to 
inundations  and  occasions  of  drying  up.  In  conse- 
quence of  losing  their  water,  the  seas,  he  thought, 
had  in  places  become  so  shallow  that  the  bottom 
showed  through. 

Plausible  on  the  surface,  this  theory  breaks  down  so 
soon  as  it  is  subjected  to  quantitative  criticism.  For 
the  moment  we  try  to  track  the  water,  we  detect  the 
inadequacy  of  the  clew.  The  enormous  areas  over 
which  the  phenomenon  occurs  necessitates  the  estab- 
lishing an  alibi  for  all  the  lost  water  that  has  gone. 
Drying  up  on  such  a  scale  would  mean  the  removal 
of  many  feet  of  liquid  over  hundreds  of  thousands  of 


116  MAES   AND  ITS   CANALS  CHAI-.  x 

miles  in  extent.  To  produce  any  such  change  in  ap- 
pearance as  we  witness,  even  on  the  supposition  that 
these  seas  were  none  too  deep  to  start  with,  would  in- 
volve lowering  the  level  of  the  water  by  from  five  to 
twenty  feet  throughout  two  thirds  of  the  whole  sur- 
face of  the  southern  hemisphere.  This  would  leave  a 
heap  of  waters  to  be  accounted  for,  bewildering  in  its 
immensity.  The  myriad  tons  of  it  must  be  disposed  of ; 
either  by  drainage  into  other  regions  or  by  being  caught 
up  into  the  sky. 

In  this  emergency  it  might  seem  at  first  as  if  the  polar 
cap  of  the  opposite  hemisphere  offered  itself  as  a  possible 
reservoir  for  the  momentarily  superfluous  fluid.  But 
such  hoped-for  outlet  to  the  problem  is  at  once  closed 
by  the  simple  fact  that  when  the  lightening  of  the  dark 
regions  of  the  southern  hemisphere  takes  place,  the 
opposite  polar  cap  has  already  attained  its  maximum; 
in  fact,  has  already  begun  to  melt.  It,  therefore,  abso- 
lutely refuses  to  lend  itself  to  any  such  service.  This 
was  not  known  to  Schiaparelli's  time,  the  observations 
which  have  established  it,  by  recording  more  completely 
the  history  of  the  cap,  having  since  been  made.  In- 
deed, it  was  not  known  even  at  the  time  when  the  writer, 
in  1894,  showed  the  impossibility  of  the  transfer  on  other 
grounds;  to  wit,  on  the  fact  of  no  commensurate  con- 
comitant darkening  of  the  surface  elsewhere  and  on  the 
manifest  non-complicity,  if  not  impotency,  of  the  Mar- 


THE   BLUE-GKEEN   AKEAS 


117 


tian  atmosphere  in  the  process.  The  transference  of 
the  water  to  other  dark  patches  in  the  northern  hemi- 
sphere fails  of  sufficiency  of  explanation  because  of 
the  limited  extent  of  such  areas  on  that  side  of  the 
globe;  while  the  air  is  quite  as  incapable  of  carrying 
away  any  such  body  of  liquid,  though  the  whole  of  it 
were  at  the  saturation-point,  not  to  mention  that  there 
exists  no  sign  of  the  attempt.  The  reader  will  find 
this  reasoning  set  forth  in  Mars,  published  eleven 
years  ago.  He  will  now  note,  from  what  has  been  said 
above  about  the  northern  polar  cap,  that  continued 
observations  since  have  resulted  in  opening  up  another 
line  of  proof  which  has  only  strengthened  the  conclusion 
there  reached. 

The  coup  de  grace,  however,  to  the  old  belief  was 
given  when  the  surface  of  the  dark  areas  was  found 
to  be  traversed  by  perma- 
nent lines  by  Pickering 
and  Douglass.  Continued 
observation  showed  these 
lines  to  be  unchangeable  in 
place.  Now  permanent 
lines  cannot  exist  on  bodies 
of  wrater,  and  in  conse- 
quence the  idea  that  what 
we  looked  on  there  were  water  surfaces  had  to  be 
abandoned. 


Lines  in  dark  area. 


118  MAES  AND  ITS   CANALS  CHAP,  x 

Thus  we  now  know  that  the  markings  on  both  the 
Moon  and  Mars  which  have  been  called  maria  are  not 
in  reality  seas.  Yet  we  shall  do  well  still  to  keep  the 
old-fashioned  sonorous  names,  Mare  Erythraeum,  Mare 
Sirenum,  and  their  fellows,  because  it  is  inconvenient 
to  change ;  while,  if  we  please,  we  may  see  in  their  con- 
secrated Latin  couching  the  fit  embalming  in  a  dead 
language  of  a  conception  that  itself  is  dead. 


CHAPTER  XI 

VEGETATION 

OINCE  closer  acquaintance  takes  from  the  maria 
their  character  of  seas,  we  are  led  to  inquire  again 
into  their  constitution.  Now,  when  we  set  ourselves 
to  consider  to  what  such  appearances  could  be  due  we 
note  something  besides  sea,  which  forms  a  large  part 
of  our  earth's  surface,  and  would  have  very  much 
what  we  suppose  the  latter's  aspect  from  afar  to 
be,  not  only  in  tone,  but  in  tint.  This  something  is 
vegetation.  Seen  from  a  height  and  mellowed  by 
atmospheric  distance,  great  forests  lose  their  green  to 
become  themselves  ultramarine. 

To  dispossess  a  previous  conception  is  difficult,  but 
so  soon  as  we  have  put  the  idea  of  seas  out  of  our  heads 
a  vegetal  explanation  proves  to  satisfy  the  phenomena, 
even  at  first  glance,  better  than  water  surfaces.  In 
their  color,  blue-green,  the  dark  areas  exactly  typify 
the  distant  look  of  our  own  forests;  whereas  we  are 
not  at  all  sure  that  seas  would.  From  color  alone  we 
are  more  justified  in  deeming  them  vegetal  than  marine. 
But  the  moment  we  go  farther  into  the  matter  the 
more  certain  we  become  of  being  upon  the  right  road. 

119 


120  MARS  AND  ITS   CANALS 

With  increased  detection  the  markings  they  reveal  and 
the  metamorphoses  they  undergo,  while  pointing  away 
from  water,  point  as  directly  to  vegetation.  All  the 
inexplicabilities  which  the  supposition  of  water  in- 
volves find  instant  solution  on  the  theory  of  vegetal 
growth.  The  non-balancing  of  the  areas  of  shading 
in  their  shift  from  one  part  of  the  disk  to  another,  no 
longer  becomes  a  circumstance  impossible  to  explain, 
but  a  necessary  consequence  of  their  new-found  char- 
acter, denoting  the  time  necessary  for  vegetation  to 
sprout.  The  change  of  hue  of  vast  areas  from  blue- 
green  to  ochre  no  longer  presupposes  the  bodily  trans- 
ference of  thousands  of  tons  of  substance,  but  the  quiet 
turning  of  the  leaf  under  autumnal  frosts.  Even  the 
fact  that  they  occupy  those  regions  most  fitted  by  figure 
to  contain  oceans  fits  in  with  the  same  conception. 
For  that  the  Martian  equivalents  of  forest  and  moor- 
land, tree  and  grass,  should  grow  now  in  the  lowest 
parts  of  the  planet's  surface  is  what  might  not  unrea- 
sonably be  expected  from  the  very  fact  of  their  being 
low,  since  what  remained  of  the  water  would  tend 
both  on  the  surface  and  in  the  air  to  drain  into  them. 
For  the  change  in  question  to  be  vegetal  it  must  occur 
at  the  proper  season  of  the  planet's  year.  This  we  must 
now  consider.  We  have  said  that  Schiaparelli  de- 
tected change  in  the  blue-green  regions  and  suspected 
this  change  of  seasonal  affiliation.  He  inferred  this 


iS  si 
OE  ladmsosa  .steb 


120 

With  increased  A 
the  inetaim>rpli-  I 
from  water,  point 
inexpli'-abilities   \vh>  : 
volves  rind  instant 
growth.     The  non-bala.ii< 

:/ir  .shift  from  one  part  • 
longer  becomes  a  circumstance  imp- 
but  a  BOCWffy  consequence  of  tb 

denoting  the  time  n-  - 
sprout.     The  change  of  hue  of  \    - 

en  to  orhr"  00  longer  presupposes  ii;>-  *H*iil 

ferer,.  Mafti^^^nSeV  36li 

turl,  it'imnril  1 

t-.l(.,  is  most  fitted  by  fyrur 

to  (,,  'he  same  con= 

to  of  fore> 

par! 

.\-pected  , 

low.    ftaoe   what    remained   of    t1 
l)oth  on  the  surfarc  and  in  the 
For  the  chungi'  in  (juest  ion  to  l  * 
the  proper  «seaaon  of  the  p 
now   consider.     \\?   have 

:ed  change  in  th 
this  clianire  of   ^-asonal 


Vs 


' 


CHAP,  xi  .       VEGETATION  121 

from  piecing  together  the  aspects  of  different  seasons 
of  different  years  as  shown  in  consecutive  Martian  oppo- 
sitions. To  mark  it  actually  take  place  in  a  single  Mar- 
tian year  came  later.  In  1894,  at  Flagstaff,  the  south- 
ern hemisphere  was  presented  during  its  late  spring 
and  early  summer ;  it  was  observed,  too,  for  many  of 
our  months  in  succession.  During  this  time  the  planet 
was  specially  well  circumstanced  for  study  of  the 
change  in  that  hemisphere,  both  by  reason  of  the  ap- 
positeness  of  the  season  and  of  the  unusual  size  of  the 
disk.  Advantage  was  taken  of  the  double  event  to 
a  recording  of  the  consecutive  appearances  certain 
regions  underwent,  and  the  contrasted  states  thus  ex- 
hibited were  such  as  clearly  to  betoken  the  action  of 
seasonal  change.  What  Schiaparelli  had  thus  ably 
inferred  from  diverse  portions  of  different  Martian 
years  was  in  this  case  shown  occurring  in  one  and  the 
same  semestral  cycle. 

Usually  the  change  of  hue  seems  essentially  one  of 
tone;  the  blue-green  fades  out,  getting  less  and  less 
pronounced,  until  in  extreme  cases  only  ochre  is  left 
behind.  It  acts  as  if  the  darker  color  were  superim- 
posed upon  the  lighter  and  could  be  to  a  greater  or  less 
extent  removed.  This  is  what  Schiaparelli  noted  and 
what  was  seen  in  1894  at  Flagstaff.  Three  views  en 
suite  of  the  chain  of  changes  then  observed  are  shown 
in  Mars,  the  region  known  as  Hesperia  being  central 


122  MARS  AND  ITS   CANALS  CHAP,  xi 

in  each.  Comparison  of  the  three  discloses  a  remark- 
able metamorphosis  in  that  "  promontory/'  a  rise  into 
visibility  by  a  paling  of  its  complexion.  Nor  is  the 
contrast  confined  to  it;  changes  as  salient  will  be 
noticed  in  the  pictures  over  the  other  parts  of  the  disk. 

There  have  been  instances,  however,  of  a  metamor- 
phosis so  much  more  strange  as  to  deserve  exposition 
in  detail ;  one  where  not  tone  simply  is  involved,  but 
where  a  quite  new  tint  has  surprisingly  appeared. 

On  April  19,  1903,  when,  after  being  hidden  for 
thirty  days,  owing  to  the  different  rotation  periods  of  the 
two  planets,  the  Mare  Erythraeum,  the  largest  blue- 
green  region  of  the  disk  and  lying  in  the  southern  hemi- 
sphere, rounded  again  into  view,  a  startling  transforma- 
tion stood  revealed  in  it.  Instead  of  showing  blue- 
green  as  usual,  and  as  it  had  done  six  weeks  before,  it 
was  now  of  a  distinct  chocolate-brown.  It  had  been 
well  seen  at  its  previous  presentation,  so  that  no  doubt 
existed  of  its  then  tint.  At  that  time  the  Martian  sea- 
son corresponded  to  December  30  in  our  calendar. 
Eighteen  Martian  days  had  since  elapsed,  and  it  was 
now  January  16  there.  The  metamorphosis  had  taken 
place,  therefore,  shortly  after  the  winter  solstice  of  that 
part  of  the  planet.  The  color  change  that  had  super- 
vened proved  permanent.  For  the  next  night  the 
region  showed  the  same  brown  hue,  and  so  it  contin- 
ued to  appear  throughout  the  days  that  it  was  visible. 


Nl>   ITS   < 

a  of  the  tlm 

in  that  try,"  a  ri> 

puling  of  i  ion.     Nor  ; 

•rd  to  it;    ehnaipBC  as  salient  \v 
•d  in  the  picture  -«ther  parts  of  the 

rhere  have  been  inatnaww.  ;    \vever,  of  a  metamor- 
so  much  iiioi-'.    -  >•*  to  deserve  exposition 

in  detail;   one  when  simply  is  involved,  but 

where  a  quite  new  >  "prisingly  appeared, 

i  >n   April   19,    19u  after  being   I- 

•  lays, owing  to  t  h< :•  <liflw*  n\  rotation  periods  of  the 
two  planets,  th<  vthrtwum,  the  largest  blue- 

green  region  of  the  <i;:-k    Mare  Erytlffiiuflt  he  s-  -ill  iicni 
Martian  date.  January  16. 

sphere,  rounded  again  ns:  •  startling  transf 
tion  stood  re\<  '.stead  of  showing  blue- 
green  as  usual  EU  -lone  six  weeks  before,  it 
\\as  now  of  a  dil  ..-ro-brown.     It  had  been 
well  seen  at  itsprev  Cation,  so  that  no  doubt 

'  of  its  then  tfl  he  Nfartian  sea- 

-|K>iirh'«l   to    1 1- 
Eighteefi  Martian  (i 

now  January  16  thc-i  M  !:t!norj>hosiri  had  taken 
place,  there  fore,  shortly  after  the  winter  solstice  of  that 
part  of  the  planet.  The  color  change  that  had  super- 
vened proved  porrruJiK-M!  ;•  ••  .  night  the 

showed  the  same  it  contin- 
ued to  appear  throughuM 


VEGETATION 


128 


Two  months  passed,  and  then  the  chocolate  hue  had 
vanished,  —  gone  as  it  had  come,  —  and  the  mare 
had  resumed  its  usual  tint,  except  for  being  some- 
what pale  at  the  south.  It  had  come  to  be  Febru- 
ary 21  on  Mars.  Timed  and  tabulated,  the  meta- 
morphosis through  which  the  mare  passed  stands 
out  thus :  — 

MARE  ERYTHRAEUM  1903 


DAYS  BEFORE  OR 

MUNDANE 
DATE 

AFTER  SUMMER 
SOLSTICE 
(BEFORE  =  — 

MARTIAN 
DATE 

ASPECT 

AFTER      =  +) 

February  16 

-10 

December  16 

Blue-green 

March  20 

+  22 

January  1 

Blue-green 

April  19 

52 

January  16 

Chocolate 

April  22 

55 

January  18 

Chocolate 

May  26 

89 

February  4 

Faint  chocolate 

May  30 

93 

February  6 

Faint  chocolate 

June  30 

123 

February  22 

Faint  blue-green 

July? 

130 

February  25 

Faint  blue-green 

The  culmination  of  the  transformation  seems  to  have 
taken  place  about  60  days  after  the  southern  winter 
solstice,  or  in  the  depth  of  the  Martian  winter  of  that 
hemisphere.  This  is  certainly  just  the  time  at  which 
vegetation  should  be  at  its  deadest. 

The  northern  and  southern  portions  of  the  mare  did 
not  behave  alike  in  taking  on  the  chocolate  tint. 
From  the  notes  made  about  them  during  the  opposition 
it  appears  that  the  latter  was  later  than  the  former  in 


124 


MARS   AND   ITS   CANALS 


undergoing  the  metamorphosis,  as  will  be  seen  from 
the  following  depth  of  the  blue  green  estimated  in 
percentages  shown  at  different  dates,  calling  the  deepest 
tone  ever  exhibited  by  it  unity. 


MARTIAN 

DECEMBER 

JANUARY 

JANUAR'Y 

FEBRUARY 

FEBRUARY 

DATE, 

(16) 

(1) 

(17) 

(5) 

(24) 

Northern 

50 

50 

0 

25 

50 

Southern 

50 

50 

0 

0 

25 

From  this  table  we  may  place  the  lowest  point  of  the 
blue-green  tint  as  reached  about  the  22d  of  Janu- 
ary for  the  northern,  the  5th  of  February  for  the 
southern,  part.  This  would  indicate  that  the  wave 
of  returning  growth  came  from  the  north,  not  the  south ; 
an  important  fact,  as  we  shall  see  later  in  studying  the 
action  of  the  canals. 

At  the  next  opposition,  in  1905,  a  recurrence  of  the 
transformation  was  watched  for,  and  not  in  vain.  It 
occurred,  however,  somewhat  later  in  the  Martian  sea- 
son. On  December  27  of  the  planet's  current  year  the 
Mare  Erythraeum  was  still  as  usual,  blue-green,  nothing 
out  of  the  ordinary  being  remarked  in  it ;  and  so  it  was 
on  its  January  17,  although  the  southern  edge  was  darker 
than  the  northern.  It  looked  certainly  as  if  the  meta- 
morphosis were  this  year  to  be  omitted.  But  such 
was  not  the  case.  When  the  region  again  came  round, 
on  February  1  of  the  Martian  calendar,  there  the  strange 


. 

j'ws,  as  WH 
blue  •  • 


C24) 


28 


oint  of  the 


Mare  Erythraeum 
Martian  date.  February  1 


transf 

occurred. 


tttid  not  in  vain.     It 
no  Martian  sea- 


son.    On  1  -t's  current  year  the 

Man-  ErythnuMun  \v:»e«  .-till  a»s  usual,  blue-green,  ni  •• 
out  of  the  ordinary  being  remarked  in  it 
emit  Ltbough  the  sotitb 

than  '  "11.      It  looked  r« ••••• 

inorp)!Dsi>    were    this  year  1<>    '•••-• 

''•   .• 
iTiiar    1  of  the  Ma v^ 


o 


VEGETATION 


125 


tint  was  as  unmistakable  as  it  had  been  on  its  original 
occurrence.  Not  only  was  the  Mare  Erythraeum  so 
colored,  but  on  February  5  (Martian)  the  northern  por- 
tion of  the  Mare  Cimmerium  was  observed  to  be  simi- 
larly affected.  In  the  Mare  Erythraeum  the  anomalous 
chocolate  hue  was  confined  to  a  belt  between  the  lati- 
tudes of  10°  and  20°  south  of  the  equator ;  in  the  Mare 
Cimmerium  it  stretched  a  little  higher,  from  10°  at  the 
west  to  25°  at  the  east.  It  is  noteworthy  that  the 
southern  portion  of  the  latter  showed  blue  at  the  time 
the  northern  showed  brown.  Then  the  metamor- 
phosis proceeded  as  shown  in  the  following  table: — 
MARE  ERYTHRAEUM  1905 


MUNDANE 
DATE 

DAYS  AFTER  WINTER 
SOLSTICE  OF  SOUTHERN 
HEMISPHERE 

MARTIAN 
DATE 

ASPECT 

January  25 

12 

December  27 

Blue-green 

March  6 

52 

January  16 

Blue-green 

April  4 

81 

January  31 

Chocolate 

April  12 

89 

February  4 

Chocolate 

April  30 

107 

February  13 

Faint  chocolate 

May  8 

115 

February  17 

Faint  chocolate 

May  12 

119 

February  19 

Faint  blue-green 

June  11 

149 

March  6 

Faint  blue-green 

June  15 

153 

'  March  8 

Faint  blue-green 

July  16 

184 

March  23 

Pale  bluish  green 

Here,  as  in  1903,  a  chromatic  rise  and  fall  is  evident ; 
the  culmination  of  the  change  occurring  in  Martian  early 
February  about  ninety  days  after  the  winter  solstice. 
That  it  was  not  of  long  duration  is  also  indicated.  If 


126 


MARS   AND   ITS   CANALS 


we  examine  the  evidence  for  the  two  portions  of  the 
mare  separately,  the  northern  and  the  southern,  as  in 
1903,  we  find  it  as  follows :  — 


MARTIAN 

DECEMBER 

JANUARY 

FEBRUARY 

FEBRUARY 

MARCH 

MARCH 

DATE, 

(27) 

(16) 

(2) 

(16) 

(7) 

(23) 

Northern 

50 

50 

0 

10 

25 

30 

Southern 

50 

50 

20 

20 

25 

30 

Here  again  a  slight  retardation  in  the  advent  of  the 
metamorphosis  is  observable  in  the  southern  portion. 

There  would  seem  to  be  a  difference  in  the  time  of  the 
change  between  the  two  years  of  fifteen  days,  1905 
being  by  that  much  the  later.  But  with  points 
of  reference  themselves  thirty  days  apart,  it  is 
possible  the  two  more  nearly  coincided  than  here  ap- 
pears. 

Unlike  the  ochre  of  the  light  regions  generally,  which 
suggest  desert  pure  and  simple,  the  chocolate-brown 
precisely  mimicked  the  complexion  of  fallow  ground. 
When  we  consider  the  vegetal-like  blue-green  that  it 
replaced,  and  remember  further  the  time  of  year  at 
which  it  occurred  upon  both  these  Martian  years,  we 
can  hardly  resist  the  conclusion  that  it  was  something 
very  like  fallow  field  that  was  there  uncovered  to  our 
view. 

From  the  recurrence  of  the  phenomenon  on  two  suc- 
cessive years,  it  is  likely  that  it  annually  takes  place. 


muer  : 

^iJ 


126  ALS 

xamine  t ;  two  portions  of  the 

mare  sepur;..;  the  southern,  as  in 
1903.  we 


advent  of  the 
tin  it  hern  portion. 

the  tin  i  e  of  the 
of  fifteen  days, 


Mare  Elythraeufrt.  •i  t      with 
Martian  elate,  February  21 

apart,    it    is 
-    "wncided  than  here  ap- 


:  ions  generally,  which 

t  lie    i 
.    <  :' 

blue-gre<  : 
the  time 

-Martian  years,  we 
r  was  something 
ficovered  t 

.  • 


T 


CHAP,  xi  VEGETATION  127 

That  it  is  seasonal  can  scarcely  be  doubted  from  the 
timeliness  of  its  occurrence,  and  that  different  portions 
of  its  terrane  successively  underwent  their  metamor- 
phosis shows  further  that  it  followed  a  law  peculiar 
to  the  planet,  to  which  we  shall  be  introduced  when  we 
come  to  consider  the  phenomena  of  the  canals. 

Instances  of  relative  hue  in  different  dark  patches 
corroboratory  of  seasonal  variation,  and  therefore  of 
vegetal  constitution,  might  easily  be  adduced.  Thus, 
in  1905  during  the  summer  of  the  northern  hemisphere, 
the  Mare  Acidalium  was  notably  darker  than  the  Mare 
Erythraeum  to  the  north  of  it,  which  is  what  the  law 
of  seasonal  variation  would  require,  since  it  was  June 
in  the  one,  December  in  the  other  at  the  time.  But  we 
need  not  to  add  example  to  example  or  proof  to  proof, 
for  there  are  no  phenomena  that  contradict  it.  We 
conclude,  therefore,  that  the  blue-green  areas  of  Mars 
are  not  seas,  but  areas  of  vegetation.  Just  as  reasoning 
to  a  negative  result  drifts  us  to  the  first  conclusion,  so 
reasoning  to  a  positive  one  lands  us  at  the  second. 


CHAPTER   XII 

TERRAQUEOUSNESS   AND   TERRESTRIALITY 

TTTITH  the  vanishing  of  its  seas  we  get  for  the  first 
time  solid  ground  on  which  to  build  our  Martian 
physiography.  The  change  in  venue  from  oceans  to 
land  has  produced  a  complete  alteration  in  our  judg- 
ment of  the  present  state  of  the  planet.  It  destroys 
the  analogy  which  was  supposed  to  exist  between  Mars 
and  our  earth,  and  by  abolishing  the  actuality  of  oceans 
there,  seems,  metaphorically,  to  put  us  at  first  all  the 
more  at  sea  in  our  attempt  to  understand  the  planet. 
But  looked  at-  more  carefully,  it  turns  out  to  explain 
much  that  was  obscure,  and  in  so  doing  gives  us  at  once 
a  wider  view  of  the  history  of  planetary  evolution. 

The  trait  concerned  is  cosmic.  Study  of  the  several 
planets  of  our  solar  system,  notably  the  Earth,  Moon, 
and  Mars,  reveals  tolerably  legibly  an  interesting  phase 
of  a  planet's  career,  which  apparently  must  happen 
to  all  such  bodies,  and  evidently  has  happened  or  is 
happening  to  these  three:  the  transition  of  its  sur- 
face from  a  terraqueous  to  a  purely  terrestrial  con- 
dition. The  terraqueous  state  is  well  exhibited  by 
our  own  earth  at  the  moment,  where  lands  and 

128 


CHAP,  xii  TERRESTRIALITY  129 

oceans  share  the  surface  between  them.  The  ter- 
restrial is  exemplified  by  both  the  Moon  and  Mars, 
on  whose  surfaces  no  bodies  of  water  at  present  exist. 
That  the  one  state  passes  by  process  of  development 
into  the  other  I  shall  now  give  my  reasons  for 
believing. 

In  the  first  place  the  appearance  of  the  dark  markings 
both  on  the  Moon  and  Mars  hints  that  though  seas 
no  longer,  they  were  seas  once  upon  a  time.  On  the 
moon,  not  only  does  their  shape  suggest  this  previous 
condition,  but  the  smooth  and  even  look  of  their  sur- 
faces adds  to  the  cogency  of  the  inference.  More  im- 
portant, however,  than  either  of  these  characteristics, 
and  confirmatory  of  both,  is  the  fact  that  the  great 
tracts  in  question  seem  to  lie  below  the  level  of  the  cor- 
rugated surface,  which  is  thickly  strewn  with  volcanic 
cones.  Their  level  and  their  levelness  fay  in  explana- 
tion into  one  another.  The  first  makes  possible  the 
former  presence  of  water;  the  second  speaks  of  its 
effect.  For  their  flat  character  hints  that  these  areas 
were  held  down  at  the  time  when  the  other  parts  of 
the  surface  were  being  violently  thrown  up.  That 
they  can  themselves  be  cooled  lava  flows,  their  extent 
and  position  seem  enough  to  negative ;  to  say  nothing 
of  the  fact  that  they  should  in  that  case  lie  above, 
not  below,  the  general  level.  Something,  therefore, 
covered  them  during  the  moon's  eruptive  youth  and 


130  MARS  AND   ITS   CANALS  CHAP,  xn 

disappeared  later.  Such  superincumbence  may  well 
have  been  water,  under  which  the  now  great  plains  lay 
then  as  ocean  bottoms.  Deep-sea  soundings  in  our 
own  oceans  betray  an  ocean  floor  of  the  same  exten- 
sive sort,  diversified  as  on  the  moon.  To  call  the 
lunar  maria  seas  may  not  be  so  complete  a  misnomer 
after  all ;  but  only  a  resurrecting  in  epitaph  what  was 
the  truth  in  its  day. 

Only  doubtfully  offered  here  for  the  Moon,  for 
Mars  the  inference  seems  more  sure.  Here  again  the 
dark  regions  not  only  look  as  they  should  had  they 
had  an  earlier  history,  but  they,  too,  seem  to  lie  below 
the  level  of  the  surface  round  about.  When  they  pass 
over  the  terminator  they  invariably  show  as  flatten- 
ings  upon  it,  as  if  a  slice  of  the  surface  had  been  pared 
off.  Such  profile  in  such  pass  is  what  ground  at  a 
lower  level  would  present.  Undoubtedly  a  part  of  the 
seeming  depression  is  due  to  relative  absence  of  irradi- 
ation consequent  upon  a  more  sombre  tint,  but  loss 
of  light  hardly  seems  capable  of  the  whole  effect.  In 
the  case  of  Mars,  then,  as  with  the  Moon,  a  mistaken 
inference  builded  better  than  it  knew,  if,  indeed,  we 
should  rightly  consider  an  inference  to  be  mistaken 
which  on  half  data  lands  us  at  the  right  door. 

From  the  aspects  of  the  dark  regions  we  are  led, 
then,  to  regard  Mars  as  having  passed  through  that  stage 
of  existence  in  which  the  earth  finds  itself  at  the  mo- 


CHAP,  xn  TEKEESTRIALITY  131 

ment,  the  stage  at  which  oceans  and  seas  form  a  feature 
of  its  landscape  and  an  impediment  to  subjugation  of 
its  surface  in  its  entirety.  What  once  were  ocean  beds 
have  become  ocean  bottoms  devoid  of  that  which 
originally  filled  them. 

That  the  process  of  parting  with  a  watery  envelop 
is  an  inevitable  concomitant  of  the  evolution  of  a  planet 
from  chaos  to  world,  we  do  not  have  to  go  so  far  afield 
as  Mars  and  the  Moon  for  testimony.  Scrutiny  reveals 
as  much  in  the  history  of  our  own  globe.  Two  sign- 
posts of  the  past,  one  geologic,  the  other  paleon- 
tologic,  point  unmistakably  in  this  direction.  The 
geologic  guides  us  the  more  directly  to  the  goal. 

Study  of  the  earth's  surface  reveals  the  preponderat- 
ing encroachment  of  the  land  upon  the  sea  since  both 
began  to  be,  and  demonstrates  that,  except  for  local 
losses,  the  oceans  have  been  contracting  in  size  from 
archaic  times.  So  much  is  evidenced  by  the  successive 
places  upon  which  marine  beds  have  been  laid  down. 
This  suggests  itself  at  once  as  a  theoretic  probability 
to  one  considering  the  matter  from  a  cosmic  standpoint, 
and  it  is  therefore  the  more  interesting  and  conclusive 
that,  from  an  entirely  different  departure-point,  it 
should  have  been  one  of  the  pet  propositions  of  the 
late  Professor  Dana,  who  worked  out  conclusively  the 
problem  for  North  America,  and  published  charts 
detailing  the  progressive  making  of  that  continent. 


132 


MARS  AND   ITS   CANALS 


So  telling  is  this  reclaiming  by  nature  of  land  from 
the  sea  that  it  will  be  well  to  follow  Dana  a  little  into 
detail,  as  the  details  show  effectively  the  continuity  of 
the  process  acting  through  a?ons  of  geologic  time.  At 


Map  of  North  America  at  the  close  of  Archaean  time,  showing  approximately 
the  areas  of  dry  land.    (From  Dana's  "  Manual  of  Geology.'') 

the  beginning  of  the  Archaean  age,  or,  in  other  words, 
at  the  epoch  when  stratified  beds  were  first  laid  down, 
the  earth  reached  a  turning-point  in  its  history. 
Erosion,  superficial  and  sub-aerial,  then  set  in  to  help 
restrict  the  domain  of  the  sea.  At  this  juncture  North 
America  consisted  of  a  sickle  of  terrane  inclosing  Hud- 


CHAP,  xii  TEERESTRIALITY  133 

son's  Bay  and  coming  down  at  its  apex  to  a  point  not 
much  removed  from  where  Ottawa  now  stands,  in 
about  latitude  45°  —  a  Labradorian  North  America 
only.  This,  the  kernel  of  the  future  continent,  curi- 
ously symbolized  the  form  that  continent  was  later  to 
take.  For  its  eastern  edge  was  roughly  parallel  to  the 
present  Atlantic  coastline,  although  much  within  and 
to  the  north  of  it,  while  its  western  one  was  similarly 
aligned  afar  off  to  the  now  Pacific  slope.  Besides  this 
continent  proper,  the  Appalachian,  Rocky  Mountain, 
Sierra  Nevada,  and  Sierra  Madre  chains  stood  out  of  the 
ocean  in  long,  narrow  ridges  of  detached  land,  outlining 
in  skeleton  the  bones  of  the  continent  that  was  to  be. 
The  Black  Hills  of  Dakota  and  other  highlands  made 
here  and  there  islets  in  the  sea. 

Much  the  same  backbone-showing  of  continents  yet 
to  be  filled  out  was  true  of  Europe,  Asia,  and  South 
America.  In  Europe  the  northern  countries  constituted 
all  that  could  be  called  continental  land.  Most  of 
Norway,  Sweden,  Finland,  Lapland,  existed  then,  while 
the  northern  half  of  Scotland,  the  outer  Hebrides,  por- 
tions of  Ireland,  England,  France,  and  Germany  stood 
out  as  detached  islands.  From  this,  which  is  a  fair 
sample  of  the  proportion  of  land  then  to  land  now  over 
the  other  continents  so  far  as  they  are  geologically 
known,  we  turn  to  consider  more  in  detail  the  history 
of  North  America. 


134 


MAES   AND   ITS   CANALS 


By  the  time  the  Upper  Silurian  period  came  in,  the 
Appalachian  highlands  there  had  been  greatly  extended 
and  joined  to  the  Labradorian  mainland  by  continuous 


North  America  at  the  opening  of  the  Upper  Silurian.     (From  Dana's 
"Manual  of  Geology.") 

territory;  otherwise,  no  important  addition  had  oc- 
curred, though  islands  emerged  in  Ohio,  Kentucky,  and 
Missouri. 

At  the  commencement  of  the  Carbonic  era  what  are 
now  the  Middle  states  had  begun  to  fill  up  from  the 
north,  and  Newfoundland,  from  a  small  island  in  the 
Upper  Silurian,  had  become  a  great  promontory  of 
Labrador,  while  the  Eastern  states  region  and  Nova 
Scotia  had  risen  into  being.  The  movements  closing 


CHAP,  xii  TEKRESTRIALITY  135 

Paleozoic  time  upheaved  from  low  islands  the  Ap- 
palachian chain.  The  earth's  crust  here  crumpled 
by  contraction  upon  itself;  and  the  movement  ended, 


Map  of  North  America  after  the  Appalachian  Revolution.     (From  Dana's 
"  Manual  of  Geology.") 

as  Dana  says,  by  making  dry  land  of  the  whole  eastern 
half  of  the  continent,  along  substantially  its  present 
lines. 

Mesozoic  time  was  the  period  of  the  making  of  the 
West.  It  was  an  era  of  deposition  and  coincident  sub- 
sidence, when  the  western  land  had  its  nose  just  above 
water  at  one  moment  to  be  submerged  the  next. 
Though  on  the  whole  this  part  of  the  continent  was 
emerging,  the  fact  was  that,  synchronously  with  the 


136 


MARS  AND   ITS   CANALS 


sinking  of  the  sea,  much  of  the  land  from  time  to  time 
sank  too.  The  contraction  which  raised  the  Appala- 
chian Mountains  at  the  beginning  of  the  period  and  that 


North  America  in  the  Cretaceous  period.     (From  Dana's  "  Manual  of 

Geology.") 

of  the  Rockies  at  its  close  overdid  the  necessities  of  the 
case  and  caused  subsidence  elsewhere.  The  south- 
eastern portion  of  the  continent  suffered  most,  the  West 
on  the  whole  materially  gaining.  In  the  Triassic  and 
Jurassic  eras  the  gain  was  pronounced;  it  occurred  in 
the  Cretaceous  also,  but  with  much  alternation  of  loss. 
Finally,  at  the  close  of  the  Cretaceous,  the  continent, 
except  for  a  prolonged  Gulf  of  Mexico  and  vast  internal 
lakes,  was  substantially  complete. 
The  filling  up  of  these  lakes  and  the  reclaiming  of 


TERRESTEIALITY 


137 


land  from  the  Gulf  of  Mexico  constituted  the  land- 
making  work  of  Tertiary  times.  The  extent  of  the 
lakes  in  the  Eocene  era  is  held  to  show  that  the  general 


Map  of  North  America,  showing  the  parts  under  water  in  the  Tertiary  Era; 
the  vertically  lined  is  the  Eocene.     (From  Dana's  "  Manual  of  Geology.") 

level  of  the  mountain  plateau  was  low  and  rose  later. 
So  that  the  gain  by  the  land  at  this  time  was  greater 
than  the  map  allows  to  appear.  By  the  beginning  of 
the  Quaternary  epoch  the  continents  had  assumed 
their  present  general  area,  and  since  then  their  internal 
features  have  alone  suffered  change. 

A  similar  rising  from  the  sea  fell  to  the  lot  of  Europe, 
though  it  has  not  been  detailed  with  so  much  care.  The 
skeleton  of  that  continent  was  at  the  beginning  of 
depositary  time  much  what  it  is  to-day,  but  a  great  in- 


138  MARS  AND   ITS   CANALS  CHAP,  xn 

land  sea  occupied  the  centre  of  it,  which,  as  time  went 
on,  was  gradually  silted  in  and  evaporated  away, 
notably  during  the  Upper  Silurian  period. 

From  all  this  it  is  pretty  clear  that,  side  by  side  with 
alternating  risings  and  sinkings  of  the  land,  there  was 
a  tolerably  steady  gain  in  the  contest  by  which  dry 
ground  dispossessed  the  sea.  We  may,  of  course, 
credit  this  to  a  general  deepening  of  the  ocean  bottoms 
due  to  crumpling  of  the  crust,  but  we  may  also  impute 
it  to  a  loss  of  water,  and  that  the  latter  is,  at  least  for 
a  part,  in  the  explanation  the  condition  of  the  Moon 
and  Mars  makes  probable. 

Paleontology  has  the  same  story  of  reclamation  to 
tell  as  geology,  and  with  as  much  certainty,  though  its 
evidence  is  circumstantial  instead  of  direct  and  speaks 
for  the  growing  importance  of  the  land  in  the  globe's 
economy  since  the  beginning  of  depositary  time,  and 
thus  inferentially  to  its  increasing  extent.  Fossil 
remains  of  the  plants  and  creatures  that  have  one  after 
the  other  inhabited  the  earth  show  that  the  land  has 
been  steadily  rising  both  in  floral  and  faunal  estimation 
as  a  habitat  from  the  earliest  ages  to  the  present  day. 
The  record  lies  imprinted  in  the  strata  consecutively 
laid  down,  and  except  for  gaps  reads  as  directly  on  in 
bettering  domicile  as  in  evolutionary  development. 

In  Archaean  times  we  find  no  undisputed  evidence 
of  life  either  vegetal  or  animal.  But  beds  of  graphite 


CHAP,  xii  TERKESTRIALITY  139 

and  of  limestone  point  to  the  possible  existence  of  both. 
Even  anthracite  has  been  found  in  Arch^an  rocks  in 
Norway  and  also  in  Rhode  Island.  Whether  Dawson's 
Eozoon  Canadense  be  a  rhizopod  or  a  crystal,  doctors 
of  science  disagree.  Dana,  while  admitting  nothing 
specific,  deems  it  antecedently  probable  that  alga3 
and  later  microscopic  fungi  related  to  bacteria  existed 
then,  living  in  water  well  up  toward  the  boiling-point. 
Indeed,  it  is  practically  certain  that  invertebrate  life 
existed,  because  of  its  already  well-developed  character 
in  the  next  era.  The  like  antedating  is  inferable  for 
the  whole  record  of  the  rocks.  Relatively  their  history 
is  undoubtedly  fairly  accurate,  but  absolutely  it  must 
be  shifted  bodily  backward  into  the  next  preceding  era 
to  correspond  with  fact  not  yet  unearthed. 

In  the  Lower  Cambrian,  when  first  the  existence  of 
life  becomes  a  certainty,  that  life,  so  far  as  known,  was 
wholly  invertebrate  and  wholly  marine;  rhizopods 
(probably),  sponges  and  corals,  echinoderms,  worms, 
brachiopods,  mollusks,  and  crustaceans  grew  amid 
primitive  seaweed  and  have  left  their  houses  in  the  shape 
of  shells  while  perishing  themselves.  Their  tracks 
too  have  thus  survived.  The  trilobites,  crustaceans 
somewhat  resembling  our  horseshoe  crab,  were  the 
lords  of  the  Cambrian  seas  and  marked  the  point  to 
which  organic  evolution  had  then  attained.  Their 
aquatic  character  as  well  as  their  simple  type  is  shown 


140  MARS   AND   ITS   CANALS  CHAP,  xn 

by  their  thoracic  legs  having  each  a  natatory  append- 
age. 

In  the  next  era,  the  Lower  Silurian,  the  fauna  and 
flora  were  still  marine,  although  of  a  higher  order  than 
before,  and  in  the  Trenton  period,  the  upper  part  of  the 
era,  the  earliest  vertebrates,  fishes,  come  upon  the  scene : 
ganoids  and  possibly  sharks.  Nothing  terrestrial  of 
this  period  has  yet  with  certainty  been  unearthed  in 
America.  Europe  would  seem  to  have  either  been  more 
advanced  then  or  better  studied  since,  for  there  the 
first  plant  higher  than  a  seaweed  has  been  dug  up,  one 
of  a  fresh-water  genus  betokening  the  land;  while  in 
keeping  with  this  the  first  insect,  an  hemipter,  also  has 
been  disinterred.  Both  the  geography  and  the  life  of 
the  Eopaleozoic  period  Dana  styles  "thalassic." 

Neopaleozoic  time,  beginning  with  the  Upper  Silu- 
rian, marked  the  emergence  of  the  continents,  and  fol- 
lowing them  the  emergence  of  life  from  the  water  on  to 
this  land.  In  the  lower  beds  of  the  Upper  Silurian  in 
America  we  find  only  the  aquatic  forms  of  previous 
strata,  but  in  a  higher  one  we  come  in  marshes  upon 
plants  related  to  the  equiseta  or  horsetails.  In 
England  land  plants  appear  for  the  first  time  in  these 
latest  Silurian  beds  and  in  the  schists  of  Angers  have 
been  preserved  ferns.  In  both  the  old  world  and  the 
new  fossil  fishes  are  found  and  the  oldest  terrestrial 
species  of  scorpions.  But  the  great  bulk  of  forms  was 


CHAP,  xii  TERRESTEIALITY  141 

still  marine;  corals,  crinoids,  brachiopods,  trilobites 
constituting  the  principal  inhabitants.  At  this  time 
the  seas  were  warm,  having  much  the  same  temperature 
between  65°  and  80°  north  as  between  30°  and  45°; 
the  prevalence  of  a  general  temperate  tropicality  being 
shown  by  the  fact  that  the  common  tropical  chain 
corals  lived  in  latitude  82°  north. 

In  the  Devonian  era,  the  Old  Red  Sandstone,  fishes 
grew  and  multiplied,  increasing  in  size  apparently 
through  the  era,  and  in  the  last  period  of .  it  reaching 
their  culminating  point.  These  pelagic  vertebrates 
much  surpassed  in  structure  the  terrestrial  population 
of  the  time,. which  was  of  a  low  type  and  consisted  of 
invertebrates  such  as  myriapods,  spiders,  scorpions, 
and  insects;  for  the  land  was  only  making.  In  the 
mid-Devonian,  forests  of  a  primitive  kind  covered  such 
country  as  there  was,  an  amphibious  land,  composed 
of  jungles  and  widespread  marshes.  Tree  ferns  made 
the  bulk  of  the  vegetation,  but  among  them  grew  also 
cycads  and  yews.  Mammoth  may-flies  flitted  through 
the  gloom  of  these  old  forests,  but  no  vertebrate  as  yet 
had  left  the  sea. 

Following  upon  the  Old  Red  Sandstone  were  laid 
down  the  Carbonic  strata,  and  with  the  Carbonic  en- 
tered upon  the  scene  the  advance  scouts  of  an  army 
of  progress  evolutionarily  impelled  to  spy  out  the  land 
—  the  first  amphibians.  They  made  their  debut  in  the 


142  MAKS   AND   ITS   CANALS  CHAP.  x,i 

Subcarboniferous  section  of  the  era,  the  oldest  of  the 
three  periods  into  which  the  Carbonic  is  divided, 
crawling  out  of  the  sea  to  return  again  and  leaving  but 
footprints  at  first  on  the  sands  of  time.  In  the  second 
period,  the  Coal-measures  proper,  they  ventured  so  far 
as  to  leave  their  skeletons  on  terra  firma,  or  rather 
infirma,  while  their  tracks  there  show  them  to  have 
been  now  in  great  numbers.  In  this  manner  the  an- 
cestors of  the  oldest  land  inhabitants  began  to  struggle 
out  of  the  sea.  In  the  Permian,  the  third  and  latest 
period  of  paleozoic  times,  we  find  their  descendants 
established  in  their  new  habitat,  for  in  it  we  come  upon 
the  first  reptiles.  Such  possession  marks  a  distinct 
step  up  in  function  as  in  fact,  for  while  amphibians 
visited  dry  land,  reptiles  made  it  their  home.  The 
getting  out  of  the  water  had  now,  in  the  case  of  the 
more  evolved  forms,  become  an  accomplished  fact. 
The  reptiles  were,  indeed,  the  lowest  and  most  general- 
ized of  their  class,  Rhynchocephalians,  " beak-headed" 
species  that  by  their  teeth  proclaim  their  marine 
origin  and  their  relationship  to  the  great  amphibians 
that  still  felt  undecided  where  to  stay.  Meanwhile, 
in  Europe  dragon-flies,  two  feet  across,  possessed  the 
air;  while  amphibians  there,  as  here,  ancestrally  pre- 
ceded reptiles  in  occupying  the  land. 

Mesozoic  times  were,  par  excellence,  the  age  of  mon- 
sters;   for   the   Triassic    (the   New   Red   Sandstone), 


CHAP,  xii  TERKESTKIALITY  143 

Jurassic  and  Cretaceous  eras  marked  the  reign  of  the 
reptiles.  Great  dinosaurs  sleep  still  in  the  Triassic 
strata  of  the  Atlantic  border  and  in  the  Jurassic  of  the 
Western  states,  to  be  unearthed  from  time  to  time 
and  be  given  mausolea  in  our  museums.  Gigantic 
they  were  and  very  literally  possessed  the  earth.  In 
Europe  they  were  substantially  as  in  America  during 
these  mesozoic  eras,  and  showed  their  dominance  by 
long  survival  in  time  as  well  as  world- wide  distribution 
in  space;  for  they  lived  all  the  way  from  Kansas  to 
New  Zealand  and  from  the  Trias  to  the  Upper  Cre- 
taceous. It  is  supposed  by  Professor  Osborn  that  many 
of  them,  like  the  herbivorous  brontosaurus,  waded  in 
marshes,  not  wholly  unlike  in  habit  to  the  modern 
hippopotamus.  Others  were  land-stalking  carnivores, 
like  the  megalosaurs  of  a  little  later  date.  Of  enormous 
size,  the  largest  exceeded  any  animal  which  has  ever 
lived,  the  whales  alone  excepted;  the  biggest,  the 
atlantosaurus  and  the  brontosaurus,  reaching  a  length 
of  sixty  feet.  For  all  their  bulk  they  had  scant  brains, 
just  enough  to  enable  them  to  feed  and  wallow,  prob- 
ably. It  is  interesting  to  note  that  many  of  the  rep- 
tiles, the  less  adventurous,  apparently  reverted  to  the 
sea.  For  though  the  crocodilians  existed  already  in 
the  Trias,  the  plesiosaurians  did  not  come  in  till  the 
Middle  Trias  in  Europe,  and  the  sea-serpents  (mosasau- 
rus)  till  the  Upper  Cretaceous. 


144  MARS   AND   ITS   CANALS  CHAP,  xn 

Though  the  dinosaurs  dominated  life  in  those  days, 
higher  forms,  their  descendants,  unnoticed  were  gradu- 
ally creeping  in,  eventually  to  supplant  them.  For 
brain  was  making  its  way  unobtrusively  in  the  earliest 
of  the  mammals,  diminutive  creatures  at  first  and  of  the 
lowest  type.  First  appearing  in  the  Trias  as  some- 
thing approaching  the  missing  link  between  reptiles 
and  mammals,  they  later  developed  into  monotremes 
and  marsupials,  not  rising  in  differentiation  above  the 
latter  order  to  the  end  of  Mesozoic  times.  And  this 
both  in  the  old  world  and  the  new.  In  the  Jurassic,  too, 
flying  lizards  and  the  first  birds  appeared,  showing 
their  pedigree  in  their  teeth. 

With  Cenozoic  times  we  come  upon  the  first  true  or 
placental  mammals  with  their  culmination  up  to  date 
in  man.  In  the  Eocene  they  were  of  a  primitive  type ; 
they  were  also  of  a  comprehensive  one,  fitted  to  eat  any- 
thing. From  this  tjiey  specialized,  some  evolving  and 
some  on  the  whole  devolving ;  the  whale,  for  instance, 
taking  to  the  water  in  the  Eocene  through  the  same 
degenerate  proclivity  that  had  characterized  the  sea- 
saurians  ages  before.  The  earth  was  growing  colder, 
though  still  fairly  warm,  and  with  the  fall  in  tempera- 
ture the  higher  types  of  life  antithetically  rose,  evolu- 
tion gradually  fitting  them  to  cope  with  more  advanced 
conditions.  In  this  manner  did  the  land  supplant  the 
sea  as  the  essential  feature  of  the  earth's  surface,  first, 


CHAP,  xii  TEERESTKIALITY  145 

in  coming  into  being,  and  then,  by  offering  conditions 
fraught  with  greater  possibilities,  as  the  habitat  of  the 
most  advanced  forms  of  life,  both  plants  and  animals. 

The  possibility  of  advance  in  evolution  was  largely 
due  to  the  fact  that  the  land  did  thus  supplant  the  sea. 
Spontaneous  variation,  the  as  yet  unexplained  pri- 
mum  mobile  in  the  genesis  of  species,  is  probably  to  be 
referred  to  chemism  and  is  likely  later  to  receive  its 
solution  at  the  hands  of  that  science.  In  the  meanwhile 
it  is  evident  that  unless  the  variation  obtain  encourage- 
ment from  the  environment  no  advance  in  type  occurs. 
Now  the  land  offers  to  an  organism  sufficiently  evolved 
to  benefit  by  it,  opportunities  the  sea  does  not  possess. 
First  of  these,  undoubtedly,  is  the  care  it  enables  to  be 
given  to  the  young.  To  cast  one's  brood  upon  the 
waters  is  not  the  best  method  of  insuring  its  bringing  up. 
There  is  too  much  of  the  uncertainties  of  wave  and  cur- 
rent to  make  the  process  a  healthy  one,  and  even  when 
attached  to  rocks  and  seaweed,  the  attachment  to  a 
mother  is  to  be  preferred.  Without  a  period  of  in- 
fancy, when  the  young  is  unable  to  do  for  itself,  no  great 
development  is  possible.  In  the  only  striking  excep- 
tion, the  case  of  the  whales,  dolphins,  and  porpoises, 
size  has  probably  counted  for  much  in  the  matter,  while 
the  development  of  the  cetaceans  is  far  behind  that 
of  the  majority  of  land  mammals. 

Change  of  place,  not  in  distance,  but  in  variety,  is 


146  MAES  AND  ITS   CANALS  CHAP,  xn 

another  factor.  The  sea  is  same  as  a  habitat,  one  square 
mile  of  it  being  much  like  another,  except  for  gradually 
changing  temperature.  The  land,  on  the  other  hand, 
from  its  accidented  surface,  presents  all  manner  of 
diversity  in  the  conditions.  And  the  more  varied  the 
conditions  to  which  the  organism  is  exposed,  the  greater 
its  own  complexity  must  be  to  enable  it  to  meet  them. 

That  the  terrestrial  stage  of  planetary  development 
is  subsequent  to  the  terraqueous  one,  and  must  of 
necessity  succeed  it  if  the  latter  ever  exist  on  a  body, 
follows  from  the  loss  of  internal  heat  on  the  one  hand 
and  from  the  kinetic  theory  of  gases  on  the  other.  To 
which  of  the  two  to  attribute  the  lion's  share  in  the 
business  is  matter  for  doubt ;  but  that  both  must  be 
concerned  in  it  we  may  take  for  certain. 

So  long  as  the  internal  heat  suffices  to  keep  the  body 
fluid,  the  liquid  itself  sees  to  it  that  all  interstices  are 
filled.  As  the  heat  dissipates,  the  body  begins  to  solidify, 
starting  with  the  crust.  For  cosmic  purposes  it  un- 
doubtedly still  remains  plastic,  but  cracks  of  relatively 
small  size  are  both  formed  and  persist.  Into  these  the 
surface  water  seeps.  With  continued  refrigeration  the 
crust  thickens,  more  cracks  are  opened  and  more  water 
given  lodgment  within,  to  the  impoverishment  of  the 
seas.  The  process  would  continue  till  the  pressure  of 
the  crust  itself  rendered  plastic  all  that  lay  below,  be- 
yond which,  of  course,  no  fissures  could  be  formed. 


CHAP,  xii  TEKKESTKIALITY  147 

How  competent  to  swallow  all  the  seas  such  earth  cuti- 
cle cracks  may  be  we  ignore ;  for  we  cannot  be  said  to 
know  much  of  the  process.  We  can  only  infer  that  to 
a  certain  extent  internal  absorption  of  surface  seas 
must  mark  a  stage  of  the  evolution  by  which  a  star 
becomes  a  world  and  then  an  inert  mass,  one  of  the 
dark  bodies  of  which  space  is  full. 

Of  the  other  means  we  know  more.  We  are  certain 
that  it  must  take  place,  though  we  are  in  doubt  as  to 
the  amount  it  has  already  accomplished.  This  method 
of  depletion  is  by  the  departure  of  the  water  in  the  form 
of  gas,  in  consequence  of  the  molecular  motions.  If  we 
knew  the  temperature  and  the  age  of  Mars  and  also 
the  amount  of  atmosphere  originally  surrounding  it, 
we  could  possibly  predicate  its  state.  Reversely,  we 
can  infer  something  as  to  age  and  temperature  from 
its  present  condition. 


CHAPTER  XIII 

THE    REDDISH-OCHRE    TRACTS 

"DOTH  for  their  evidence  and  their  extent  the  great 
ochre  stretches  of  the  disk  claim  attention  first. 
Largely  unchangeable,  these  show  essentially  the  same 
day  after  day  and  from  the  year's  beginning  to  its  end. 
In  hue  they  range  from  sand  color  to  a  brick  red ;  some 
parts  of  the  planet  being  given  to  the  one  tint,  some 
to  the  other.  It  is  to  the  latter  that  the  fiery  tint  of 
Mars  to  the  naked  eye  is  due.  The  differences  in  com- 
plexion are  local  and  peculiar,  both  in  place  and  time. 
For  though  saffron  best  paints  the  greater  part  of  the 
light  areas,  certain  localities  present  at  times  a  red 
like  that  of  our  red  sandstone.  Hellas  is  one  of  these 
ruddy  regions  and  Aeria  another.  It  is  only  on  occasion 
that  they  thus  show,  and  to  what  to  assign  their  varia- 
bility is  as  yet  matter  of  conjecture.  Possibly  it  is 
owing  to  Martian  meteorologic  condition;  possibly 
to  something  else.  But  whatever  its  origin,  the  change 
is  not  so  much  contradictory  of,  as  supplementary  to, 
the  general  fact  of  unalterableness,  which  is  after  all 
the  basic  trait  about  them  and  the  keynote  to  their 
condition. 

148 


CHAP,  xin      THE   REDDISH-OCHRE   TRACTS  149 

Land  the  ochre  regions  have  generally  been  taken  for, 
and  land  they  still  make  good  their  claim  to  be  con- 
sidered. For  the  better  they  are  seen,  the  greater  the 
ground  for  the  belief.  Indeed,  they  seem  to  be  noth- 
ing but  ground,  or,  in  other  words,  deserts.  Their 
color  first  points  them  out  for  such.  The  pale  salmon 
hue,  which  best  reproduces  in  drawings  the  general 
tint  of  their  surface,  is  that  which  our  own  deserts  wear. 
The  Sahara  has  this  look ;  still  more  it  finds  its  coun- 
terpart in  the  far  aspect  of  the  Painted  Desert  of 
northern  Arizona.  To  one  standing  on  the  summit  of 
the  San  Francisco  Peaks  and  gazing  off  from  that  iso- 
lated height  upon  this  other  isolation  of  aridity,  the 
resemblance  of  its  lambent  saffron  to  the  telescopic 
tints  of  the  Martian  globe  is  strikingly  impressive. 
Far  forest  and  still  farther  desert  are  transmuted  by 
distance  into  mere  washes  of  color,  the  one  robin's-egg 
blue,  the  other  roseate  ochre,  and  so  bathed,  both,  in 
the  flood  of  sunshine  from  out  a  cloudless  burnished 
sky  that  their  tints  rival  those  of  a  fire-opal.  None 
otherwise  do  the  Martian  colors  stand  out  upon  the 
disk  at  the  far  end  of  the  journey  down  the  telescope's 
tube.  Even  in  its  mottlings  the  one  expanse  recalls 
the  other.  To  the  Painted  Desert  its  predominating 
tint  is  given  by  the  new  red  sandstone  of  the  Trias, 
the  stratum  here  exposed;  and  this  shows  in  all  its 
pristine  nakedness  because  of  the  lack  of  water  to  clothe 


150  MARS   AND  ITS   CANALS  CHAP,  xm 

it  with  any  but  the  sparsest  growth.  Limestones  that 
crop  out  beside  it  are  lighter  yellow,  whitish  and  steel- 
gray,  and  seen  near  give  the  terrane  the  look  of  a 
painter's  palette.  Seen  from  far  they  have  rather  the 
tint  of  sand ;  and  the  one  effect,  like  the  other,  is  Mar- 
tian in  look.  And  as  if  to  assimilate  the  two  planetary 
appearances  the  more,  the  thread  of  blue-green  that 
attention  traces  athwart  the  Painted  Desert  marks 
the  line  of  cottonwoods  along  the  banks  of  the  Little 
Colorado  River  —  deserts  both,  if  look  be  any  guarantee 
of  character,  with  verdure  banding  them. 

In  other  ways  these  earthly  deserts  offer  a  parallel 
to  the  Martian.  No  desert  on  the  Earth  is  absolutely 
devoid  of  life  of  some  kind,  vegetal  and  animal.  The 
worst  conditioned  are  not  what  one  is  taught  in  child- 
hood to  believe  a  desert  to  be  —  a  vast  waste  of  sand, 
with  a  camel  and  a  palm  thrown  in  to  heighten  the 
sterility.  In  all  Saharas  outside  of  the  pages  of  the 
school  books  some  vegetation  grows,  though  it  is  com- 
monly not  of  a  kind  to  boast  of,  being  rather  a  succes 
d'estime,  as  sagebrush,  cacti,  and  the  like.  But  what 
is  of  interest  here  in  the  connection  is  its  color.  For 
it  is  commonly  of  a  more  ochreish  tint  than  usual,  in 
keeping  with  its  surroundings,  a  paling  out  of  the  green 
to  something  more  tawny,  indicating  a  relative  reduc- 
tion of  the  chlorophyll  and  an  increase  of  the  lipo- 
chromes  in  the  tissues  of  the  plant,  since  the  one  gives 


CHAP,  xui       THE   REDDISH-OCHRE   TRACTS  151 

the  green  tint  to  the  leaves,  the  other  the  yellow.  As 
this  vegetation,  poor  as  it  is,  has  its  annual  history, 
it  must  alter  the  look  of  the  desert  at  times  and  pro- 
duce precisely  those  slight  variations  in  tint  observable 
on  Mars  in  like  circumstance. 

The  Arizona  desert  dates  from  no  further  back  than 
early  Tertiary  times,  as  the  limestone  of  the  Cretaceous 
there  present  shows.  Water  then  stretched  where 
desert  now  is,  and  the  limestone  beds  were  laid  down  in 
it.  How  old  the  Martian  Saharas  are  we  have  no  means 
of  knowing.  But  one  thing  we  may  predicate  about 
both :  a  desert  is  not  an  original,  but  an  acquired,  condi- 
tion of  a  planet's  surface,  demonstrably  so  in  the  case 
of  a  planet  which  has  had  a  sedimentary  epoch  in  its 
life-history.  In  the  Arizona  desert  the  surface  is  com- 
posed of  depositary  rocks  of  Mesozoic  times,  except 
where  lava  streams  have  flowed  down  over  it  since 
then.  The  land,  then,  was  once  under  water,  and 
cannot  but  have  been  fertile  for  some  time  after  it 
emerged. 

But  we  are  not  left  to  inference  in  the  matter,  how- 
ever good  that  inference  may  be.  A  little  to  the  south 
of  the  Painted  Desert,  in  the  midst  of  the  barren  plateau 
of  northern  Arizona,  of  which  the  former  makes  a  part, 
stand  the  remains  of  a  petrified  forest.  Huge  chalced- 
ony trunks  of  trees,  so  savingly  transmuted  into  stone 
that  their  genus  is  still  decipherable,  lie  scattered  here 


152  .        MAES  AND   ITS   CANALS  CHAP,  xm 

over  the  barren  ground  in  waste  profusion,  one  of  them 
still  spanning  a  canon  just  as  it  fell  in  that,  to  it,  de- 
structive day  of  a  far  prehistoric  past.  The  rock 
stratum  on  which  their  remains  lie  is  of  Triassic  and 
Cretaceous  times  and  the  petrifications  show  that  in 
the  Cretaceous  a  stately  forest  overspread  the  land. 
In  those  days  at  least  the  spot  was  fertile  where  now 
sparse  sagebrush  and  cacti  find  a  living  hard.  Not  here 
alone  where  the  blocks  are  so  conspicuous  as  to  invite 
their  carrying  away  is  a  former  flourishing  growth  of 
vegetation  attested,  but  over  large  adjoining  areas  of 
desert  search  has  brought  the  like  past  tenancy  to  light. 
Fragments  of  what  once  were  trees  have  been  picked 
up  in  the  Little  Colorado  basin  and  in  the  neighbor- 
hood of  Ash  Fork,  on  both  sides,  that  is,  of  the  present 
forest  crown  that  covers  the  higher  part  of  the  plateau 
from  which  rise  the  San  Francisco  Peaks.  In  the  blue 
distance  the  mountains  look  down  verdure-clad  upon 
a  now  encircling  waste,  but  one  which  in  earlier  eras 
was  as  pine-bearing  as  they.  Their  lofty  oasis  is  all 
that  is  now  left  of  a  once  fertile  country;  the  retreat 
of  the  trees  up  the  slopes  in  consequence  of  a  dimin- 
ishing rainfall,  until  a  rise  of  two  thousand  feet  from 
what  once  was  timber-land  is  necessary  to  reach  the 
tree-line  of  today,  being  typical  of  'desert  lands,  and 
testifying  to  greater  aqueous  affluence  in  the  past. 
In  the  same  manner  streams  descend  from  the  cedar- 


CHAP,  xin      THE   BEDDISH-OCHRE   TKACTS  153 

clad  range  of  the  Lebanon  to  lose  themselves  in  the 
Arabian  desert  just  without  the  doors  of  Damascus; 
and  Palestine  has  desiccated  within  history  times. 
Palestine,  a  land  once  flowing  with  milk  and  honey, 
can  hardly  flow  poor  water  now,  and  furnishes  another 
straw  to  mark  the  ebbing  of  the  water  supply. 

This  making  of  deserts  is  not  a  sporadic,  accidental, 
or  local  matter,  although  local  causes  have  abetted  or 
hindered  it.  On  the  contrary,  it  is  an  inevitable  result 
of  planetary  evolution,  a  phase  of  that  evolution  which 
follows  from  what  has  been  said  in  Chapter  XII  on 
the  abandonment  of  a  planet  by  its  water.  Deserts 
are  simply  another  sign  of  the  same  process.  The  very 
aging  which  began  by  depriving  a  body  of  its  seas 
takes  from  it  later  its  forest  and  its  grass.  A  growing 
scarcity  of  water  is  bound  to  depauperate  the  one,  as  it 
depletes  the  other.  We  have  positive  proof  of  the 
action  in  our  own  deserts.  For  these  bear  testimony, 
in  places  at  least,  to  not  having  always  been  so,  but 
to  have  gradually  become  so  within  relatively  recent 
times.  But  we  have  more  general  proof  of  the  action 
from  the  position  occupied  on  the  earth's  surface  by  its 
deserts. 

The  significant  fact  about  the  desert-making  so 
stealthily  going  on  is  that  only  certain  zones  of  the 
earth's  surface  are  affected.  Those  belting  the  two 
tropics  of  Cancer  and  Capricorn,  for  several  degrees 


154  MAES   AND  ITS   CANALS  CHAP,  xm 

on  either  side  of  them,  most  exhibit  the  phenomenon. 
Such  positioning  of  the  deserts  is  not  due  to  chance. 
Directly,  of  course,  desertism  is  due  to  dearth  of  rain. 
This  in  turn  depends  on  the  character  and  condition 
of  the  winds.  If  a  wind  laden  with  moisture  travel 
into  a  colder  region  of  the  globe,  its  moisture  is  pre- 
cipitated in  rain  and  we  have  a  fertile  country ;  if  it 
voyage  into  a  warmer  clime  it  takes  up  what  little 
moisture  may  be  there  already  and  a  desert  is  the 
result. 

Now  our  system  of  winds  is  such  as  to  produce  a  fall 
of  rain  for  the  different  latitudes,  as  tabulated  by 
Supan,  thus :  — 

Zone    I  40°N-27°N  Little  rain  in  summer  but  much  in  winter. 
II  27  N-19  N  Little  rain  at  all  seasons. 

III  19  N-  7  N  Little  rain  in  winter  but  much  in  summer. 

IV  7  N-  1  N  Abundant  rain  at  all  seasons. 

V    1  N-17  S  Little  rain  in  winter  but  much  in  summer. 
VI  17  S-30  S  Little  rain  at  all  seasons. 
VII  30  S-35  S   Little  rain  in  summer  but  much  in  winter. 

Zones  II  and  VI,  the  zones  of  minimum  rainfall,  are 
also  those  in  which  the  deserts  occur.  The  northern 
one  traverses  southern  California,  Arizona,  New  Mexico, 
the  Sahara,  Arabia,  and  the  Desert  of  Gobi ;  the  south- 
ern, Peru,  the  South  African  veldt,  and  central  Aus- 
tralia. The  belts  are  wavy  bands  which  by  their 
form  betray  both  a  general  underlying  trend  to  drought 


CHAP,  xiii       THE   REDDISH-OCHRE   TRACTS  155 

at  these  parallels  and  also  the  effect  of  local  topography 
in  the  matter. 

From  being  distributed  thus  in  belts,  it  is  evident  that 
the  deserts  are  general  globe  phenomena,  and  from  their 
being  found  only  in  the  zones  of  least  rainfall,  that  the 
earth  has  itself  entered,  though  not  far  as  yet,  upon 
the  desert  stage  of  its  history.  Once  begun,  the  desert 
areas  must  perforce  spread  as  water  becomes  scarce, 
invading  and  occupying  territory  in  proportion  as  the 
rainfall  there  grows  small. 

Now  the  axial  tilt  of  Mars  is  almost  exactly  the  same 
as  that  of  our  Earth,  the  latest  determinations  from 
the  ensemble  of  measures  giving  24°  for  it.  Here,  then, 
we  have  initial  conditions  reproducing  those  of  the 
earth.  But  from  the  smaller  size  of  the  planet  that 
body  would  age  the  earlier,  since  it  would  lose  its  inter- 
nal heat  the  more  rapidly,  just  as  a  small  stone  cools 
sooner  than  a  larger  one.  On  general  principles, 
therefore,  it  should  now  be  more  advanced  in  its  plan- 
etary career.  In  consequence,  desertism  should  have 
overtaken  more  of  its  surface  than  has  yet  happened 
on  earth,  and  instead  of  narrow  belts  of  sterility  we 
should  expect  to  find  there  Saharas  of  relatively  vast 
extent. 

Now,  such  a  state  of  things  is  precisely  what  the 
telescope  reveals.  The  ochre  tracts  occupy  nine  tenths 
of  the  northern  hemisphere  and  a  third  of  the  southern. 


156 


MARS   AND   ITS  CANALS 


CHAP.   XIII 


Three  fifths,  therefore,  of  the  whole  surface  of  the 
planet  is  a  desert. 

Of  cosmic  as  well  as  of  particular  import  is  the  corre- 
lation thus  made  evident  between  the  physical  prin- 


Desert  areas. 

ciples  that  effect  the  aging  of  a  planet  and  the  aspect 
Mars  presents.  Experimental  corroboration  of  those 
laws  is  thus  afforded,  while,  reversely,  confidence  in 
their  applicability  is  increased.  With  continued  ob- 
servation the  planet  appears  more  desiccate  as  im- 
proved conditions  bring  it  nearer.  Dry  land  as  it 


CHAP,  xni       THE   REDDISH-OCHRE   TRACTS  157 

was  thought  to  be  proves  even  drier,  something  which 
lacks  water  for   the  ordinary  necessities  of  a  living 
worjd. 
The  picture  the  planet  offers  to  us  is  thus  arid  beyond 


Desert  areas. 

present  analogue  on  Earth.  Pitiless  as  our  deserts 
are,  they  are  but  faint  forecasts  of  the  state  of  things 
existent  on  Mars  at  the  present  time.  Only  those  who 
as  travelers  have  had  experience  of  our  own  Saharas 
can  adequately  picture  what  Mars  is  like  and  what  so 
waterless  a  condition  means.  Only  such  can  understand 


158  MARS   AND  ITS   CANALS 


CHAP.    XIII 


what  is  implied  in  having  the  local  and  avoidable  thus 
extended  into  the  unescapable  and  the  world- wide ;  and 
what  a  terrible  significance  for  everything  Martian  lies 
in  that  single  word :  desert. 


CHAPTER   XIV 

SUMMARY 

TF,  now,  we  review  with  the  mind's  eye  the  several 
features  of  Mars  which  we  have  surveyed  with  the 
bodily  one,  we  shall  be  surprised  to  find  to  what  they 
commit  us.  Suggestive  as  each  is  considered  by  itself, 
the  ensemble  into  which  they  combine  proves  of  mul- 
tiplicate  force  in  its  implication.  For  each  turns  out 
to  fit  into  place  in  one  consistent  whole,  a  scheme  of 
things  in  which  are  present  all  the  conditions  necessary 
to  the  existence  and  continuance  of  those  processes 
which  constitute  what  we  call  life.  In  short,  we  are 
conducted  with  a  cogency,  which  grows  as  we  consider 
it,  to  the  conclusion  that  Mars  is  habitable. 

Two  ways  of  appreciating  this  cogency  are  open  to  us. 
We  may  treat  it  with  the  simple  reasoning  of  common- 
sense,  as  we  should  a  dissected  map  or  a  piece  of  ma- 
chinery in  which  we  realize  we  are  right  when  the 
several  parts  at  last  fit  together  and  the  picture  stands 
revealed  or  the  machine  works.  Or  we  may  subject 
the  evidence  to  quantitative  estimates  for  and  against 
by  the  doctrine  of  probabilities,  and  thus  evaluate 
the  chances  of  its  being  correct.  Consciously  or  un- 

159 


160  MARS  AND  ITS   CANALS  CHAP,  xiv 

consciously,  this  is  what  we  are  about  in  our  decisions 
every  day  of  our  lives.  At  the  one  end  of  the  line  are 
those  skillful  judgments  where  the  balance  .is  so  keen- 
edged  that  the  least  overweight  on  the  one  side  dips  the 
scales  to  a  conclusion.  At  the  other  extremity  stand 
those  deductions  which  we  usually  speak  of  as  proved, 
such  as  the  law  of  gravitation.  But  both  assurances 
rest  really  upon  probability  and  differ  only  in  degree. 
What  we  mean  by  proof  of  anything  is  that  a  suppo- 
sition advanced  to  account  for  it  explains  all  the  facts 
and  is  not  opposed  to  any  of  them,  and  that  the  balance 
of  probability  in  consequence  is  very  largely  in  its  favor. 

Now,  if  several  pieces  of  evidence,  distinct  in  their 
origin,  concur  to  a  given  conclusion,  the  probability 
that  that  conclusion  is  correct  is  far  greater  than  what 
results  from  each  alone;  and  mounts  up  soon  to  some- 
thing much  exceeding  what  bettors  at  races  call  cer- 
tainty odds.  However  unversed  the  average  man  may 
be  in  calculating  the  probability,  he  recognizes  the  fact 
in  his  dealings  with  his  fellows  by  the  way  he  attaches 
weight  to  concurrent  testimony.  It  is  such  concurrent 
evidence  that  we  have  now  to  consider.  To  this  end 
we  will  marshal  the  several  facts  ascertained  in  a  sum- 
marized list  for  their  easier  intercomparison. 

These  facts  are: — 

j      (1)  Mars  turns  on  its  axis  in  24  h.  37  m.  22.65  s.  with 
reference  to  the  stars,  and  in  24  h.  39  m.  35.0  s.  (as  a 


CHAP,  xiv  SUMMARY  161 

mean)  with  regard  to  the  Sun.  Its  day,  therefore, 
is  only  about  forty  minutes  longer  than  ours. 
^  (2)  Its  axis  is  tilted  to  the  plane  of  its  orbit  by  about 
23°  59'  (most  recent  determination,  1905).  This  gives 
the  planet  seasons  almost  the  counterpart  of  our  own 
in  character ;  but  in  length  nearly  double  ours,  for 

4,  (3)  Its  year  consists  of  687  of  our  days,  669  of  its 
own. 

/§  (4)  Polar  caps  are  plainly  visible  which  melt  in  the 
Martian  summer  to  form  again  in  the  Martian  winter, 
thus  implying  the  presence  of  a  substance  deposited 
by  cold. 

(5)  As  the  polar  caps  melt,  they  are  bordered  by  a 
blue  belt,  which  retreats  with  them.    This  excludes  the 
possibility  of  their  being  formed  of  carbon  dioxide,  and 
shows  that  of  all  the  substances  we  know  the  material 
composing  them  must  be  water. 

(6)  In  the  case  of  the  southern  cap,  the  blue  belt  has 
widenings  in  it  in  places.    These  occur  where  the  blue- 
green  areas  bordering  upon  the  polar  cap  are  largest. 

(7)  The  extensive  shrinkage  of  the  polar  snows  shows 
their  quantity  to  be    inconsiderable,   and  points  to 
scanty  deposition  due  to  dearth  of  water. 

(8)  The  melting  takes  place  locally  after  the  same 
general  order  and  method,  Martian   year  after  year, 
both  in  the  south  cap, 

(9)  And  in  the  north  one.    This  is  evidenced  by  the 


162  MAKS   AND   ITS   CANALS  CHAP,  xiv 

recurrence  of  rifts  in  the  same  places  annually  in  each. 
i  ^   The  water  thus  let  loose  can,   therefore,   be  locally 

counted  on. 

^  (10)  That  the  south  polar  cap  is  given  to  greater 
extremes  than  the  north  one,  implies  again,  in  view 
of  the  eccentricity  of  the  orbit  and  the  tilt  of  the  axis, 
that  deposition  in  both  caps  is  light. 

(11)  The  polar  seas  at  the  edges  of  the  caps  being 
temporary  affairs,  the  water  from  them  must  be  fresh. 

(12)  The  melting  of  the  caps  on  the  one  hand  and 
their  reforming  on  the  other  affirm  the  presence  of 
water  vapor  in  the  Martian  atmosphere,  of  whatever 
else  that  air  consist. 

(13)  Since   water  vapor   is    present,  of  which  the 
molecular   weight  is    18,  it  follows  from  the   kinetic 
theory  of  gases  that  nitrogen,  oxygen,  and  carbonic 
acid,  of  molecular  weights  28,  32,  and  38  respectively, 
are  probably  there,  too,  owing  to  being  heavier. 

(14)  The  limb-light  bears  testimony  to  this  atmos- 
phere. 

(15)  The  planet's  low  albedo  points  to  a  density 
for  the  atmosphere  very  much  less  than  our  own. 

(16)  The  apparent  evidence  of  a  twilight  goes  to  con- 
firm this. 

(17)  Permanent  markings  show  upon  the  disk,  prov- 
ing that  the  surface  itself  is  visible. 

(18)  Outside  of  the  polar  cap  the  disk  is  divided  into 


CHAP,  xiv  SUMMARY  163 

red-ochre  and  blue-green  regions.  The  red-ochre 
stretches  have  the  same  appearance  as  our  deserts 
seen  from  afar, 

(19)  And  behave  as  such,  being  but  little  affected 
by  change.        ,1    \. 

(20)  The    blue-green    areas    were    once     thought 
to  be  seas.    But  they  cannot  be  such,  because  they 
change  in  tint  according  to  the  Martian  season,  and  the 

^4 — • 

area  and  amount  of  the  lightening  is  not  offset  at  the 
time  by  corresponding  darkening  elsewhere; 

(21)  Nor  by  any  augmentation  of  the  other  polar 
cap  or  precipitation  into  cloud.     It  cannot,  therefore, 
be  due  to  shift  of  substance. 

(22)  Furthermore,  they  are  all  seamed  by  lines  and 

T^ 

spots  darker  than  themselves  which  are  permanent  in 
place ;  so  that  there  can  be  no  bodies  of  water  on  the 
planet. 

_  (23)  On  the  other  hand,  their  color,  blue-green,  is 
that  of  vegetation;  this  regularly  fades  out,  as  vege- 
tation would,  to  ochre  for  the  most  part,  but  in  places 
changes  to  a  chocolate-brown. 

(24)  The  change  that  comes  over  them  is  seasonal 
in  period,  as  that  of  vegetation  would  be. 

(25)  Each    hemisphere    undergoes    this    metamor- 
phosis in  turn. 

(26)  That  it  is  recurrent  is  again  proof  positive  of 
an  atmosphere. 


164  MAKS  AND  ITS  CANALS  CHAP,  xiv 

(27)  The  changes  are  metabolic,  since  those  in  one 
direction  are  later  reversed  to  a  restoration  of  the  origi- 
nal status.     Anabolic  as  well  as  katabolic  processes 
thus  go  on  there ;  that  is,  growth  as  well  as  decay  takes 
place.    This  proves  them  of  vegetal  origin. 

(28)  The  existence  of  vegetation  shows  that  carbonic 
acid,  oxygen,  and  undoubtedly  nitrogen,  are  present  in 
the  Martian  atmosphere,  since  plants  give  out  oxygen 
and  take  in  carbonic  acid. 

(29)  The  changes  in  the  dark  areas  follow  upon  the 
melting  of  the  polar   caps,  not   occurring  until  after 
that  melting  is  under  way; 

(30)  And  not  immediately  then,  but  only  after  the 
lapse  of  a  certain  time. 

(31)  Though  not  seas  now,  from  their  look  the  dark 
areas  suggest  old  sea  bottoms,  and  when  on  the  ter- 
minator appear  as  depressions  (whether  because  really 
at  a  lower  level  or  because  of  less  illumination  is  not 
certain). 

(32)  That  they  are  now  the  parts  of  the  planet  to 
support  vegetation  hints  the  same  past  office,  as  water 
would  naturally  drain  into  them.    That  such  a  meta- 
morphosis should   occur   with   planetary  aging  is   in 
keeping  with  the  kinetic  theory  of  gases. 

|£  (33)  Terminator  observations  prove  conclusively 
that  there  are  no  mountains  on  Mars,  but  that  the 
surface  is  surprisingly  flat. 


CHAP,  xiv  SUMMARY  165 

(34)  But  they  do  reveal  clouds  which  are  usually 
rare  arid  are  often,  if  not  always,  dust-storms. 

(35)  White   spots  are   occasionally   visible,  lasting 
unchanged  for  weeks,  in  the  tropic  and  temperate  re- 
gions, showing  that  the  climate  is  apparently  cold, 

(36)  But  at  the  same  time  proving  that  most  of  the 
surface  has  a  temperature  above  the  freezing-point. 

(37)  In  winter  the  temperate  zones  are  more  or 
less  covered  by  a  whitish  veil,  which  may  be  hoar-frost 
or  may  be  cloud. 

(38)  A  spring  haze  surrounds  the  north  polar  cap 
during  the  weeks  that  follow  its  most  extensive  melting. 

(39)  Otherwise  the  Martian  sky  is  perfectly  clear; 
like  that  of  a  dry  and  desert  land. 

The  way  in  which  these  thirty-nine  articles  fit  into 
one  another  to  a  mortised  whole  is  striking  enough  at 
first  sight,  but  becomes  more  and  more  impressive  the 
more  one  considers  it.  For  some  are  due  to  one  kind 
of  observation,  some  to  another.  In  the  taking  they 
are  unrelated;  yet  in  the  result  they  agree.  Equally 
pregnant  is  the  history  of  their  acquisition.  Most  of 
them 'were  detected  as  the  outcome  of  observations  at 
the  opposition  of  1894,  and  led  to  the  theory  which  was 
published  in  the  writer's  first  book  on  the  subject. 
Others  are  the  result  of  the  five  oppositions  that  have 
since  occurred.  These  have  proved  entirely  corrobora- 
tive of  the  previous  ones  and  of  the  theory  then  deduced, 


166  MARS  AND  ITS  CANALS  CHAP,  xiv 

and  that  in  two  distinct  ways:  first,  by  the  accumu- 
lated evidence  they  have  brought  to  the  matter  along 
the  old  lines ;  and,  secondly,  by  what  they  have  revealed 
in  new  directions.  Of  these  thirty-nine  articles  of 
Martian  scientific  faith  in  observation  or  deduction,  (9), 
(10),  (21),  (22),  (25),  (27),  (28),  (30),  (33),  (35),  (36), 
and  (38)  are  in  whole  or  part  new.  That  continued 
scrutiny  is  thus  corroborative  of  the  earlier  results,  both 
along  the  old  and  along  new  lines  of  investigation,  war- 
rants additional  confidence  in  the  conclusion. 

Considering,  now,  these  counts,  we  see  that  they 
make  reasonably  evident  on  Mars  the  presence  of :  — 

1.  Days  and  seasons  substantially  like  our  own ; 

2.  An  atmosphere  containing  water  vapor,  carbonic 
acid,  and  oxygen; 

3.  Water  in  great  scarcity; 

4.  A  temperature  colder  than  ours,  but  above  the 
Fahrenheit  freezing-point,  except  in  winter  and  in  the 
extreme  polar  regions; 

5.  Vegetation. 

First  and  foremost  of  these  is  air.  In  order  to  make 
it  possible  for  vital  processes  of  any  sort  to  take  place, 
the  body  of  a  planet  must  be  clothed  with  an  atmos- 
phere, by  the  modesty  of  nature,  the  old  astronomers 
would  have  said.  Such  a  covering  subserves  two  pur- 
poses: it  keeps  out  the  cold  of  space,  thus  permitting 
the  maintenance  of  a  temperature  sufficient  to  support 


CHAP,  xiv  SUMMARY  167 

life,  and  it  affords  a  medium  through  which  metabolism 
can  go  on. 

Now  the  presence  of  air  is  attested  first  and  foremost 
by  the  fact  of  change  in  the  Martian  markings,  (12), 
(13),  (26),  (28),  and  (35).  The  changes  observed  are 
conspicuous ;  are  both  inorganic  (in  the  case  of  the  polar 
caps),  (12),  (13),  and  (35),  and  metabolic  or  organic,  (26) 
and  (28),  (in  the  case  of  the  blue-green  areas) ;  that  is, 
they  consist  of  building  up  as  well  as  of  pulling  down 
and  are  planet-wide  in  occurrence.  Such  changes 
could  not  occur  in  the  absence  of  an  atmosphere.  They 
show  that  this  atmosphere  consists  of  water  vapor,  (5), 
carbonic  acid,  and  oxygen,  (28). 

The  limb-light,  the  apparent  evidence  of  a  twilight 
arc  and  the  planet's  low  albedo  indicate  that  this  atmos- 
phere is  thin.  The  appearance  of  the  surface,  (35),  sug- 
gests cold,  indicative  again  of  a  thin  air.  Such  tenuity 
is  in  accord  with  what  a  priori  principles  would  lead 
us  to  expect,  and  tends  to  show  that  reliance  on  general 
principles  is  here  not  misplaced,  a  point  of  some  in- 
terest. 

Lastly,  the  occurrence  of  clouds,  (34),  visibly  floating 
and  traveling  over  the  surface,  and  haze  at  times,  (38), 
proves  in  another  way  the  existence  of  the  medium  in 
which  alone  this  could  be  possible. 

Water  is  the  next  substance  vital  to  planetary  life. 
As  to  its  actual  presence  the  polar  caps,  (4)-(12),  have 


168  MAES   AND   ITS   CANALS  CIIAI-.  xiv 

most  to  say;  as  to  its  relative  absence,  the  rest  of  the 
disk,  (17)-(22).  The  forthright  conception  of  the  polar 
caps  as  composed  of  snow  and  ice  is  borne  out  by  further 
investigation  into  what  could  cause  the  observed  phe- 
nomenon. Carbonic  acid,  the  only  other  substance  we 
know  capable  in  any  way  of  resembling  what  wre  see, 
turns  out  not  capable  of  producing  one  important  de- 
tail of  the  caps'  appearance,  the  blue  band,  (5),  which 
accompanies  them  in  their  retreat.  Water  alone 
could  do  this. 

The  melting  of  the  caps  shows  that  water  vapor  must 
be  a  constituent  of  the  Martian  atmosphere.  More- 
over, as  the  molecular  weight  of  water  vapor  is  less 
than  that  of  oxygen  or  nitrogen  or  carbon  dioxide, 
if  the  former  can  exist  in  the  atmosphere  of  the  planet, 
a  fortiori  must  these  other  gases.  So  that  from  this 
we  have  knowledge  of  the  possibility  of  the  presence 
of  oxygen,  nitrogen,  and  carbon  dioxide  there.  From 
(28)  we  saw  that  their  actual  existence  is  demonstrated. 

The  next  step  is  the  ascertainment  that  the  water  is 
in  very  small  amount.  The  extensive  melting  of  the 
caps,  (7),  shows  their  quantity  to  be  inconsiderable, 
which  is  the  first  fact  pointing  to  a  dearth  of  water. 
The  second  comes  from  the  aspect  and  behavior  of  the 
reddish-ochre  regions  which  proclaim  them  deserts,  (18) 
and  (19);  the  third  from  the  detection  of  the  char- 
acter of  the  blue-green  areas  as  not  seas,  (20),  (21), 


CHAP,  xiv  SUMMARY  169 

and  (22).  In  several  different  ways,  study  of  these 
regions  asserts  their  non-aquatic  constitution,  the 
easiest  to  appreciate  being  that  they  are  traversed 
by  permanent  dark  lines  and  other  equally  sedentary 
markings,  (22).  No  bodies  of  water,  therefore,  are  to 
be  seen  outside  of  the  ephemeral  polar  seas,  immediately 
surrounding  the  caps  as  they  melt. 

This  leads  us  to  the  third  presence  on  Mars  indicative 
of  a  living  world:  vegetation.  The  other  two  spoke 
of  substances  necessary  to  life,  the  premises  in  the  case, 
this  one  of  organic  existence  itself,  its  conclusion.  The 
evidence  consists  of  static  testimony  from  the  look  of  the 
blue-green  areas,  (23),  and  of  kinematic  derived  from 
their  behavior,  (24),  (25),  (26),  and  (27).  Vegetation 
would  present  exactly  the  appearance  shown  by  them, 
and  nothing  that  we  know  of  but  vegetation  could. 
But  suggestive  as  their  appearance  is,  it  is  as  nothing 
compared  with  the  cogent  telltale  character  of  their 
behavior.  The  seasonal  change  that  sweeps  over  them 
is  metabolic,  constructive  as  well  as  destructive,  that  is, 
and  proclaims  an  organic  constitution  for  them  such  as 
only  vegetation  could  produce.  In  tint  their  metamor- 
phoses are  those  of  the  same  substance.  For  the  blue- 
green  lapses  into  ochre  and  revives  again  to  blue-green 
just  as  vegetation  does  on  our  own  Earth  at  the  proper 
season  of  the  year,  taking  both  the  Sun  .and  the  advent 
of  water  into  the  reckoning.  Furthermore,  certain 


170  MARS   AND  ITS  CANALS  CHAP,  xiv 

of  the  largest  dark  areas  turn  to  a  chocolate-brown  at 
times,  which  is  the  color  of  fallow  ground  and  sugges- 
tive, at  least,  as  occurring  where  the  blue-green  at  other 
seasons  is  the  most  pronounced.  Lastly,  the  change 
occurs  at  the  epoch  at  which,  from  a  knowledge  of  the 
melting  of  the  polar  caps,  theory  demonstrates  that  it 
ought  to  take  place  if  it  be  due  to  the  action  of 
vegetation. 

That  this  was  the  case  was  evident  from  much  less 
information  than  is  forthcoming  today;  but  what  is 
significant,  each  new  fact  discovered  about  the  planet 
goes  to  show  that  it  is  unquestionably  true. 


PAKT   II 

NON-NATURAL   FEATURES 


CHAPTER  XV 

THE    CANALS 

T^ROM  the  detection  of  the  main  markings  that  di- 
-•-  versify  the  surface  of  Mars  we  now  pass  to  a  discov- 
ery of  so  unprecedented  a  character  that  the  scientific 
world  was  at  first  loath  to  accept  it.  Only  persistent 
corroboration  has  finally  broken  down  distrust;  and, 
even  so,  doubt  of  the  genuineness  of  the  phenomena 
still  lingers  in  the  minds  of  many  who  have  not  them- 
selves seen  the  sight  because  of  the  inherent  difficulty 
of  the  observations.  For  it  is  not  one  where  confir- 
mation may  be  summoned  in  the  laboratory  at  will,  but 
one  demanding  that  the  watcher  should  wait  upon  the 
sky,  with  more  than  ordinary  acumen.  This  latter- 
day  revelation  is  the  discovery  of  the  canals. 

Quite  unlike  in  look  to  the  main  features  of  the  plan- 
et's face  is  this  second  set  of  markings  which  traverse 
its  disk,  and  which  the  genius  of  Schiaparelli  disclosed. 
Unnatural  they  may  well  be  deemed ;  for  they  are  not 
in  the  least  what  one  would  expect  to  see.  They 
differ  from  the  first  class,  not  in  degree,  but  in  kind ; 
and  the  kind  is  of  a  wholly  unparalleled  sort.  While 
the  former  bear  a  family  resemblance  to  those  of  the 

173 


174  MARS  AND  ITS  CANALS  CHAP,  xv 

earth ;  the  latter  are  peculiar  to  Mars,  finding  no  coun- 
terpart upon  the  earth  at  all. 

Introduction  "to  the  mystery  came  about  in  this  wise, 
and  will  be  repeated  for  him  who  is  successful  in  his 
search.  When  a  fairly  acute  eyed  observer  sets  himself 
to  scan  the  telescopic  disk  of  the  planet  in  steady  air, 
he  will,  after  noting  the  dazzling  contour  of  the  white 
polar  cap  and  the  sharp  outlines  of  the  blue-green  seas, 
of  a  sudden  be  made  aware  of  a  vision  as  of  a  thread 
stretched  somewhere  from  the  blue-green  across  the 
orange  areas  of  the  disk.  Gone  as  quickly  as  it  came, 
he  will  instinctively  doubt  his  own  eyesight,  and  credit 
to  illusion  what  can  so  unaccountably  disappear.  Gaze 
as  hard  as  he  will,  no  power  of  his  can  recall  it,  when, 
with  the  same  startling  abruptness,  the  thing  stands 
before  his  eyes  again.  Convinced,  after  three  or  four 
such  showings,  that  the  vision  is  real,  he  will  still  be 
left  wondering  what  and  where  it  was.  For  so  short 
and  sudden  are  its  apparitions  that  the  locating  of 
it  is  dubiously  hard.  It  is  gone  each  time  before  he 
has  got  its  bearings. 

By  persistent  watch,  however,  for  the  best  instants 
of  definition,  backed  by  the  knowledge  of  what  he  is 
to  see,  he  will  find  its  coming  more  frequent,  more 
certain  and  more  detailed.  At  last  some  particularly 
propitious  moment  will  disclose  its  relation  to  well- 
known  points  and  its  position  be  assured.  First  one 


CHAP,  xv  THE  CANALS  175 

such  thread  and  then  another  will  make  its  presence 
evident ;  and  then  he  will  note  that  each  always  appears 
in  place.  Repetition  in  situ  will  convince  him  that 
these  strange  visitants  are  as  real  as  the  main  markings, 
and  are  as  permanent  as  they. 

Such  is  the  experience  every  observer  of  them  has 
had;  and  success  depends  upon  the  acuteness  of  the 
observer's  eye  and  upon  the  persistence  with  which  he 
watches  for  the  best  moments  in  the  steadiest  air.  Cer- 
tain as  persistence  is  to  be  rewarded  at  last,  the  diffi- 
culty inherent  in  the  observations  is  ordinarily  great. 
Not  everybody  can  see  these  delicate  features  at  first 
sight,  even  when  pointed  out  to  them ;  and  to  perceive 
their  more  minute  details  takes  a  trained  as  well  as  an 
acute  eye,  observing  under  the  best  conditions.  When 
so  viewed,  however,  the  disk  of  the  planet  takes  on  a 
most  singular  appearance.  It  looks  as  if  it  had  been 
cobwebbed  all  over.  Suggestive  of  a  spider's  web  seen 
against  the  grass  of  a  spring  morning,  a  mesh  of  fine 
reticulated  lines  overspreads  it,  which  with  attention 
proves  to  compass  the  globe  from  one  pole  to  the  other. 
The  chief  difference  between  it  and  a  spider's  work  is 
one  of  size,  supplemented  by  greater  complexity,  but 
both  are  joys  of  geometric  beauty.  For  the  lines  are  of 
individually  uniform  width,  of  exceeding  tenuity,  and  of 
great  length.  These  are  the  Martian  canals. 

Two  stages  in  the  recognition  of  the  reality  confront 


176  MARS   AND   ITS   CANALS  CHAP,  xy 

the  persevering  plodder:  first,  the  perception  of  the 
canals  at  all;  and,  second,  the  realization  of  their 
very  definite  character.  It  is  wholly  due  to  lack  of 
suitable  conditions  that  the  true  form  of  the  Martian 
lines  is  usually  missed.  Given  the  proper  prerequisites 
of  location  or  of  eye,  and  their  pencil-mark  peculiarity 
stands  forth  unmistakably  confessed.  It  is  only  where 
the  seeing  or  the  sight  is  at  fault  that  the  canals  either 
fail  to  show  or  appear  as  diffuse  streaks,  the  latter  being 
a  halfway  revelation  between  the  reality  and  their  not 
being  revealed  at  all.  Much  misconception  exists  on 
this  point.  It  has  been  supposed  that  improved  at- 
mospheric conditions  simply  amount  to  bringing  the 
object  nearer  by  permitting  greater  magnification  with- 
out altering  the  hazy  look  of  its  detail.1  Not  so.  They 
do  much  more  than  this.  They  steady  the  object  much 
as  if  a  page  of  print  from  being  violently  shaken  should 
suddenly  be  held  still.  The  observer  would  at  once 
read  what  before  had  escaped  him  for  being  a  blur. 
So  is  it  with  the  canals.  In  reality,  pencilings  of  ex- 
treme tenuity,  the  agitations  of  our  own  air  spread  them 
into  diffuse  streaks;  an  effect  of  which  any  one  may 
assure  himself  by  sufficiently  rapid  motion  of  a  drawing 
in  which  they  are  depicted  sharp  and  distinct,  when  he 
will  see  them  take  on  the  streaky  look.  As  the  writer 
has  observed  them  under  both  aspects,  and  has  seen 

1  M.  Tabb6  Moreux. 


CHAP,  xv  THE   CANALS  177 

them  pass  from  the  indefinite  to  the  defined  as  the 
seeing  improved,  he  has  had  practical  proof  of  the  fact, 
and  this  not  once,  but  an  untold  number  of  times. 

Atmospheric  conditions  far  superior  to  what  are  good 
enough  for  most  astronomic  observations  are  needed 
for  such  planetary  decipherment,  and  the  observer 
experienced  in  the  subject  eventually  learns  how  all- 
important  this  is.  Under  these  conditions  the  testi- 
mony of  his  own  eyesight  upon  the  character  of  these 
markings  is  definite  and  complete.  And  the  first  trait 
that  then  emerges  from  confusion  is  that  the  markings 
are  lines;  not  simply  lines  in  the  sense  that  any  suffi- 
ciently narrow  and  continuous  marking  may  so  be 
called,  but  lines  in  the  far  more  precise  sense  in  which 
geometry  uses  the  term.  They  are  furthermore  straight 
lines.  As  Schiaparelli  said  of  them :  they  look  to  have 
been  laid  down  by  rule  and  compass.  The  very  marvel 
of  the  sight  has  been  its  own  stumbling-block  to  recog- 
nition, joined  to  the  difficulty  of  its  detection.  For  not 
only  is  the  average  observatory  not  equipped  by  nature 
for  the  task,  but  what  is  not  good  air  often  masquerades 
as  such.  Trains  of  air  waves  exist  at  times  so  fine 
as  to  confuse  this  detail,  or  even  to  obliterate  it  entirely ; 
while  at  the  same  time  they  leave  the  disk  seemingly 
sharp-cut,  with  the  result  that  one  not  well  versed 
in  such  vagaries  thinks  to  see  well  when  in  truth  he  is 
debarred  from  seeing  at  all.  When  study  of  the  condi- 


178  MAES  AND   ITS  CANALS  CHAP,  xv 

tions  finally  ends  in  putting  him  upon  the  right  road, 
the  sight  that  rewards  him  can  hardly  be  too  graphi- 
cally described. 

Next  to  the  fact  that  they  are  lines,  definiteness  of 
direction  is  the  chief  of  their  characteristics  to  strike 
the  observer.  The  lines  run  straight  throughout  their 
course.  This  is  absolutely  true  of  ninety  per  cent  of 
them,  and  practically  so  of  the  remaining  ten  per  cent, 
since  the  latter  curve  in  an  equally  symmetric  manner. 
Such  directness  has  I  know  not  what  of  immediate  im- 
pressiveness.  Quite  unlike  the  aspect  of  the  main 
markings,  which  show  a  natural  irregularity  of  outline, 
these  lines  offer  at  the  first  glance  a  most  unnatural 
regularity  of  look.  Nothing  on  Earth  of  natural  origin 
on  such  a  scale  bears  them  analogue.  Nor  does  any 
other  planet  show  the  like.  They  are,  in  fact,  distinc- 
tively Martian  phenomena.  This  is  the  first  point 
in  which  they  differ  from  the  markings  we  have  hitherto 
described.  The  others  were  generic  planetary  features ; 
these  are  specific  ones,  peculiar  to  Mars.1 

1  As  some  misrepresentation  has  been  made  on  this  subject  through 
misapprehension  of  the  writer's  observations  on  Venus  and  Mercury, 
it  may  be  well  to  state  that  the  tenuous  markings  on  both  these  other 
planets  entirely  lack  the  unnatural  regularity  distinguishing  the 
canals  of  Mars.  The  Venusian  lines  are  hazy,  ill-defined,  and  non- 
uniform;  the  Mercurian  broken  and  irregular,  suggesting  cracks. 
Neither  resemble  the  Martian  in  marvelous  precision,  and  have  never 
been  called  canals  by  the  writer  nor  by  Schiaparelli,  but  solely  by 
those  who  have  not  seen  them  and  have  misapprehended  their  char- 
acter and  look. 


CHAP,  xv  THE   CANALS  179 

Equally  striking  is  the  uniform  width  of  each  line  from 
its  beginning  to  its  end,  as  it  stands  out  there  upon  the 
disk.  The  line  varies  not  in  size  throughout  its  course 
any  more  than  it  deviates  in  direction.  It  counterfeits 
a  telegraph  wire  stretched  from  point  to  point.  Like 
the  latter  seen  afar,  the  width,  too,  is  telegraphic.  For 
it  is  not  so  much  width  as  want  of  it  that  is  evident. 
Breadth  is  inferable  solely  from  the  fact  that  the  line 
is  seen  at  all,  and  relative  size  by  difference  of  insist- 
ency. Indeed,  the  apparent  breadth  has  been  steadily 
contracting  as  the  instrumental,  atmospheric,  and  per- 
sonal conditions  have  improved.  All  three  of  the 
factors  have  conduced  to  such  emaceration,  but  the 
middle  one  the  most.  For  the  air  waves  spread  every 
marking,  and  the  effect  is  relatively  greatest  upon  those 
which  are  most  slender.  As  the  currents  of  condensa- 
tion and  rarefaction  pulse  along,  their  denser  and  their 
thinner  portions  refract  the  rays  on  either  side  of  their 
true  place,  and  thus  at  the  same  time  confuse  a  mark- 
ing and  broaden  it.  The  consequence  is  that  the  better 
the  atmospheric  conditions  and  the  more  that  has  been 
learned  about  utilizing  them,  the  finer  the  lines  have 
shown  themselves  to  be. 

Herein  we  have  a  specific  intrinsic  difference  between 
the  fundamental  features  and  these  lines:  the  main 
markings  have  extension  in  two  dimensions,  the  latter 
in  one. 


180  MAES   AND   ITS  CANALS  CHAP,  xv 

Distinctive  as  they  thus  are,  they  have,  in  keeping  with 
their  appearance,  been  given  a  distinctive  name,  that  of 
canal.  Useful  as  the  name  is  and,  as  we  shall  later  see, 
applicable,  it  must  not  be  supposed  that  what  we  see 
are  such  in  any  simple  sense.  No  observer  of  them  has 
ever  considered  them  canals  dug  like  the  Suez  Canal 
or  the  phcenix-like  Panama  one.  This  supposition 
is  exclusively  of  critic  creation. 

Their  precise  width  is  not  precisable.  They  show 
no  measurable  breadth  and  their  size,  therefore,  ad- 
mits for  certain  only  of  an  outside  limit.  They  cannot 
be  wider  than  a  determinable  maximum,  but  they  may 
be  much  less  than  this.  The  sole  method  of  estimating 
their  width  is  by  comparison  of  effect  with  a  wire  of 
known  caliber  at  a  known  distance.  For  this  purpose 
a  telegraph  wire  was  stretched  against  the  sky  at 
Flagstaff,  and  the  observers,  going  back  upon  the  mesa, 
observed  and  recorded  its  appearance  as  their  stations 
grew  remote.  It  proved  surprising  at  what  great  dis- 
tances a  slender  wire  could  be  made  out  when  thus 
projected  against  the  sky.  The  wire  in  the  experiment 
was  but  0.0726  of  an  inch  in  diameter  and  yet  could  be 
seen  with  certainty  at  a  distance  of  1800  feet,  at  which 
point  its  diameter  subtended  only  0.69  of  a  second  of 
arc.  How  small  this  quantity  is  may  be  appreciated 
from  its  taking  more  than  ninety  such  lines  laid  side 
by  side  to  make  a  width  divisible  by  the  eye.  Such 


CHAP,  xv  THE   CANALS  181 

slenderness  at  the  then  distance  of  Mars  would  corre- 
spond, under  the  magnification  commonly  used,  only 
to  three  quarters  of  a  mile.  Theoretically,  then,  a  line 
three  quarters  of  a  mile  wide  there  should  be  visible 
to  us.  Practically,  both  light  and  definition  is  lost 
in  the  telescope,  and  it  would  be  nearer  the  mark  to  con- 
sider in  such  case  two  miles  as  the  limit  of  the  percep- 
tible. With  the  planet  nearer  than  this,  as  is  often  the 
case,  the  width  which  could  be  seen  would  be  propor- 
tionally lessened.  Perhaps  we  shall  not  be  far  astray 
if  we  put  one  mile  as  the  limiting  width  which  could  be 
perceived  on  Mars  at  present,  with  distance  at  its  least 
and  definition  at  its  best. 

That  so  minute  a  quantity  should  be  visible  at  all 
is  due  to  the  line  having  a  sensible  length  and  by  sum- 
mation of  sensations  causing  to  rise  into  consciousness 
what  would  otherwise  be  lost.  A  stimulus  too  feeble 
to  produce  an  effect  upon  a  single  retinal  rod  becomes 
recognizable  when  many  in  a  row  are  similarly  ex- 
cited. 

The  experiment  furnished  another  criterion,  of  im- 
portance as  regards  the  supposition  that  the  lines  on 
Mars  are  illusory.  It  showed  that  brain-begotten  im- 
pressions of  wires  that  did  not  exist  could  be  told  from 
the  real  thing  when  the  wire  subtended  0.69  of  a  second 
of  arc  or  more;  that  below  this  the  outside  stimulus 
was  too  weak  to  differ  recognizably  from  optic  effects 


182  MARS  AND   ITS   CANALS  CHAP,  xv 

otherwise  produced;  while  when  the  real  wire  was 
diminished  to  0.59 ",  it  could  not  be  seen  at  all.  Now, 
the  majority  of  lines  on  Mars  so  far  recognized  and 
mapped  lie  in  strength  of  impression  far  above  the 
superior  limit  of  0.69 ".  To  one  versed  in  Martian  canal 
detection  there  is  no  possibility  of  self-deception  in  the 
case,  the  canals  being  very  much  more  salient  objects 
to  an  expert  than  those  who  have  not  seen  them  sup- 
pose. For  it  must  not  be  imagined  that,  when  one 
knows  what  to  be  on  the  lookout  for,  they  are  the  diffi- 
cult objects  they  seem  to  the  tyro.  Just  as  the  satel- 
lites of  Mars  were  easily  seen  once  they  were  discovered, 
so  with  these  lines. 

A  mile  or  two  we  may  take,  then,  with  safety  as  the 
smallest  width  for  one  of  the  lines.  The  greatest  was 
got  by  comparing  what  is  by  far  the  largest  canal,  the 
Nilosyrtis,  with  the  micrometer  thread.  From  such 
determination  it  appeared  that  this  canal  was  from 
25  to  30  miles  wide.  But  it  is  questionable  whether 
the  Nilosyrtis  can  properly  be  termed  a  canal,  so 
much  does  it  exceed  the  rest.  It  is  certainly  far 
larger  than  the  majority  of  them.  From  comparative 
estimates  between  its  size  and  that  of  the  others,  15 
to  20  miles  for  the  width  of  the  larger  of  the  Martian 
canals  seems  the  most  probable  value,  and  2  or  3 
miles  only  of  the  more  diminutive  of  those  so  far 
detected. 


THE   CANALS 


183 


On  the  other  hand,  the  length  of  the  canals  is  rela- 
tively enormous.  With  them  2000  miles  is  common; 
while  many  exceed  2500,  and 
the  Eumenides-Orcus  is  3540 
miles  from  the  point  where 
it  leaves  the  Phoenix  Lake 
to  the  point  where  it  enters 
the  Trivium  Charontis.  This 
means  much  more  on  Mars 
than  it  would  on  Earth, 

Owing    tO    the   Smaller    Size   Of       Sowing  the  Eumenides-Orcus. 

the  planet.  Such  a  length  exceeds  a  third  of  the 
whole  circumference  of  its  globe  at  the  equator. 
But  what  is  still  more  remarkable,  throughout  the 
whole  of  the  long  course  taken  by  the  canal,  it  swerves 
neither  to  the  right  nor  to  the  left  of  the  great  circle 
joining  the  two  points. 

Of  these  several  peculiarities  of  the  individual  canal 
it  is  difficult  to  know  to  which  to  allot  the  palm  for 
oddity,  —  great  circle  directness,  excessive  length,  want 
of  width,  or  striking  uniformity.  Each  is  so  anomal- 
ously unnatural  as  to  have  received  the  approving 
stamp  of  incredulity.  Yet  so  much,  wonderful  as  it  is, 
is  encountered  on  the  very  threshold  of  the  subject. 


CHAPTER  XVI 

THEIR   SYSTEM 

"V/TUCH  more  stands  beyond.  For,  outdoing  in 
suggestiveness  the  individual  traits  of  the  lines, 
is  the  relation  shown  by  them  to  one  another.  It  is 
the  communal  characteristics  of  the  phenomenon  that 
are  most  surprising. 

The  individual  peculiarities  of  the  lines  impress 
themselves  at  once ;  the  communal,  only  as  the  result 
of  experience,  collation,  and  thought.  As  the  observer 
becomes  trained,  the  more  lines  he  is  able  to  make  out, 
until  they  fairly  seam  the  whole  surface  of  the  light 
areas  of  the  planet.  Their  name  collectively  is  legion ; 
while  to  name  them  individually  is  fast  getting,  for  the 
number  detected,  to  be  impossible.  As  with  the  in- 
creasing family  of  asteroids,  figures  alone  will  prove 
adequate  to  the  task. 

Interdependence,  not  independence,  marks  the  atti- 
tude of  the  canals.  Each  not  only  proceeds  with  abso- 
lute directness  from  one  point  to  another,  but  at  its 
terminals  it  meets  canals  which  have  come  there  with 
like  forthrightness  from  other  far  places  upon  the  planet. 
Nor  is  it  two  only  that  thus  come  together  at  a  com- 
mon junction.  Three,  four,  five,  —  up  to  as  many  as 

184 


CHAP,  xvi  THEIR   SYSTEM  185 

fourteen,  —  thus  make  rendezvous,  and  it  is  a  poor 
junction  that  cannot  show  at  least  six  or  seven.  The 
result  is  a  network  which  triangulates  the  surface  of  the 
planet  like  a  geodetic  survey  into  polygons  of  all  shapes 
and  sizes,  the  Arian  areolas.  The  size  of  the  pieces 
forming  this  tesselate  ground  depends  solely  upon  the 
fineness  of  the  definition.  With  every  increase  in  the 
power  of  seeing,  each  areola  is  cut  into  still  smaller 
portions,  usually  by  connection  between  its  corners. 
Thus  a  polygon  or  rhombus  is  split  into  triangles  which 
may  themselves  be  divided  in  like  manner,  the  mosaic 
breaking  into  bits,  the  sides  of  which,  however,  always 
remain  clean-cut. 

From  this  arrangement  it  is  at  once  evident  that  the 
canals  are  not  fortuitously  placed.  That  lines  should 
thus  meet  exactly  and  in  numbers  at  particular  points, 
and  only  there,  shows  that  their  locating  is  not  the  out- 
come of  chance.  If  very  thin  rods  be  thrown  hap- 
hazard over  a  surface,  the  probability  that  more  than 
two  will  cross  at  the  same  point  is  vanishingly  small. 
Increasingly  assured  is  it  that  this  would  not  happen 
generally.  The  result  we  see  is  therefore  not  a  matter 
of  chance,  but  of  some  law  working  to  that  end. 

To  the  detection  of  what  that  law  is  precedes  the 
easier  ascertainment  of  what  it  is  not.  The  lines,  for 
example,  cannot  be  rivers,  which  was  the  first  explana- 
tion offered  of  them  by  Proctor  many  years  ago,  be- 


186  MARS  AND   ITS   CANALS  CHAP.™ 

cause  of  their  peculiar  straightness.  Nor  can  they  be 
channels,  the  name  given  to  them  by  Schiaparelli, 
except  in  the  non-committal  sense  in  which  he  used  the 
term.  For  here  again  their  geometric  regularity  is  bar 
to  any  estuary-like  hypothesis.  For  quite  another  rea- 
son they  cannot  be  cracks,  because  of  their  uniform 
size  throughout.  Their  unbroken  character  is  another 
fatal  objection  to  the  same  suggestion.  For  cracks  in 
ground  never  pursue  for  any  great  distance  a  continu- 
ous course,  any  more  than  they  keep  uniform  or  straight. 
The  state  of  an  old  ceiling  is  a  case  in  point.  When  it 
breaks,  it  does  so  in  fissures  that  proceed  a  certain  way, 
then  give  out  to  be  continued  by  others  roughly  parallel 
to  the  first,  but  parted  from  them.  The  same  char- 
acter is  shown  by  the  rills  on  the  moon.  The  'Straight 
Wall, '  so  called,  is  composed  of  three  such  sections,  and 
the  little  rill  to  the  right  of  it,  west  of  Birt,  of  four. 

Thus  were  they  seen  at  Flagstaff,  and  as,  to  the 
writer's  knowledge,  they  have  not  been  so  depicted 
elsewhere,  the  fact  may  serve  to  give  some  idea  of  the 
definition  there. 

That  the  underlying  cause  is  not  explosion  or  con- 
traction is  also  evidenced  by  the  canals  collectively 
as  well  as  individually,  their  arrangement  into  a  sys- 
tem, for  cracks,  however  produced,  could  only  origi- 
nate from  certain  centres  and  could  not  fit  into  those 
starting  from  others,  as  the  canals  invariably  do.  For 


CHAP,  xvi  THEIR   SYSTEM  187 

each  canal  goes  as  undeviatingly  to  one  terminal  as  it 
left  forthrightly  from  another.  If  one  wishes  to  see 
what  explosion  or  contraction  can  do,  he  has  only  to 
look  at  the  moon  through  an  opera-glass,  when  he  will 
be  shown  a  very  different  sight  from  what  the  drawings 
of  Mars  detail.  Thus  just  as,  considered  individually, 
the  lines  cannot  be  watercourses  because  of  their 
straightness,  so  they  cannot  be  cracks  because  of  dove- 
tailing into  one  another. 

The  fact  that  they  form  a  system  shows  that  what- 
ever caused  them  operated  over  the  whole  planet,  linked 
in  cause  as  in  effect  throughout  each  section.  This  at 
once  negatives  any  purely  physical  cause  of  which  we 
have  cognizance.  For  upon  a  globe  still  so  subject  to 
physical  vicissitude  as  Mars  by  its  aspect  shows  itself 
to  be,  latitude  must  tell  in  the  phenomena  its  zones 
exhibit.  Polar  snows  that  wax  and  wane  speak  of 
arctic  conditions  very  diverse  from  temperate  and 
tropic  states,  and  what  would  affect  the  one  could  not 
influence  the  other.  Yet  the  mesh  rises  superior  to 
zonal  solicitation  as  to  local  barrier.  It  is  not  some- 
thing dependent  either  on  the  temperament  or  the 
complexion  of  the  globe's  different  parts.  It  tran- 
scends surface  restriction  and  becomes  planet-wide  in  its 
working.  The  importance  of  this  omnipresence  dilates 
in  meaning  as  one  dwells  in  thought  upon  it. 

Ubiquitous  as  it  is,  the  mesh  which  thus  covers  the 


188  MAES  AND  ITS   CANALS  CHAP,  xvi 

Martian  surface  like  a  veil  spread  completely  over  it, 
is  unlike  a  veil  in  being  of  irregular  texture.  Not  only 
are  the  interstices  of  various  shape  and  pattern,  but  the 
mesh  itself  is  of  locally  differing  size.  Though  the 
threads  are  straight  and  uniform  throughout,  they  are 
not  all  alike/  besides  being  unsymmetrically  inter- 
woven. Some  are  at  least  of  ten  times  the  coarseness 
of  others,  and  from  this  fact  and  the  bo-peep  effect  of 
our  air  waves  all  are  not  visible  at  once.  In  conse- 
quence the  network  is  not  so  impressive  at  first  glance 
as  it  becomes  upon  a  synthesis  of  the  observations. 
When  this  is  done,  the  surface  proves  to  be  fairly 
evenly  cut  up,  as  recourse  to  the  maps  printed  in  this 
volume  will  amply  demonstrate.  These  maps,  as  on 
page  31,  are  made  from  the  results  of  but  one  opposi- 
tion, and  as  at  each  opposition  some  zone  is  in  a  more 
canal-showing  state  than  others,  owing  to  the  Martian 
season  at  the  time,  a  still  greater  uniformity  in  canal 
distribution  results  from  a  blending  of  many. 

From  the  completeness  of  the  mesh,  it  follows  that  in 
the  course  taken  severally  by  the  canals  no  one  direc- 
tion preponderates  over  another.  Considered  by  and 
large,  the  canals  seem  to  be  equally  distributed  round 
the  compass  points;  and  this  at  all  longitudes  and 
nearly  all  latitudes.  Tropic,  temperate,  and  even  arctic 
canals  show  a  pleasing  impartiality  in  the  matter  of 
the  course  pursued.  The  only  exceptions  occur  in  the 


THEIR   SYSTEM 


189 


neighborhood  of  the  pole.    There  a  slight  tendency 
may  be  seen  to  a  north  and  south  setting. 

Though  so  much  is  visible  in  a  general  way  from  the 
map,  it  is  of  interest  to  go  into  the  subject  with  more 
particularity  and  to  that  end  to  show  it  statistically. 
The  several  canals  traversing  each  zone  were  therefore 
counted,  and  the  area  of  the  zone  computed.  The  man- 
ner of  canal  distribution  thus  found  is  given  in  the 
following  table,  in  the  second  column  of  which  stand  the 
areas  of  the  several  zones  upon  the  planet,  each  ten 
degrees  wide,  except  the  one  next  the  snow,  and  in  the 
third  the  number  of  canals  found  traversing  them,  re- 
duced to  percentages  of  the  0°-10°  zone.  A  fourth  col- 
umn shows  the  total  length  of  the  canals  in  each  zone, 
those  from  0°  to  20°  being  taken  from  the  1896  globe, 
those  from  20°  to  90°  from  the  1903.  This  is  in  order 
to  annul  the  effect  of  the  seasons  upon  the  showing  of 
the  canals  as  much  as  possible. 


ZONE 

AREA 

No.  OF  CANALS 
WTD. 

ACTUAL  LENGTH 

0°-10° 

1.00 

1.00 

1.00 

10°  -20° 

.97 

.89 

.91 

20°  -30° 

.91 

.93 

.72 

30°  -40° 

.82 

.90 

.71 

40°  -50° 

.71 

.78 

.66 

50°  -60° 

.58 

.64 

.59 

60°  -70° 

.42 

.43 

.42 

70°  -80° 

.26 

.30 

.34 

80°  -85° 

.07 

.12 

.11 

190  MAKS  AND   ITS   CANALS  CHAP,  xvi 

The  numbers  continue  fairly  non-committal  until 
we  begin  to  approach  the  pole,  when  they  commence 
to  increase.  Much  the  same  result  is  got  if  we  take 
the  actual  canal-lengths  in  each  zone,  as  the  fourth  col- 
umn shows.  The  crowding  of  the  canals  poleward  is 
marked.  The  canals,  therefore,  are  phenomena  that 
stand  in  peculiar  relationship  to  the  polar  cap.  This 
corroborates  the  inference  about  them  due  to  their 
running  out  of  the  edge  of  the  snow.  They  not  only 
emanate  from  it,  but  they  do  so  in  Cumbers  surpassing 
what  is  elsewhere  observable  over  the  disk. 

Otherwise  is  it  with  their  departure-points.  These 
are  not  scattered  haphazard  over  the  surface,  but  bear 
to  its  general  features  definite  relations.  If  we  consider 
the  map,  obliterating  the  lines,  and  then  seek  to  connect 
the  most  salient  points  of  the  planet's  topography  by 
direct  avenues  of  communication,  we  shall  find  that  our 
putative  lines  fall  exactly  where  the  real  ones  occur. 
For  the  most  part,  the  real  lines  emanate  from  well- 
marked  indentations  in  the  dark  regions,  fitted  by 
natural  position  for  departure-points,  what,  if  these 
were  seas,  we  should  call  their  most  conspicuous  bays. 
They  thus  leave  in  the  southern  hemisphere  the  deeper 
folds  of  the  great  diaphragm,  for  the  most  part ;  though 
on  occasion  they  run  out  of  them  where  they  will. 
From  equally  conspicuous  points  in  the  dark  northern 
areas  other  lines  proceed;  while  in  the  centre  of  the 


CHAP,  xvi  THEIR   SYSTEM  191 

continents,  the  canals  make  for  more  or  less  salient 
spots,  small  patches  of  shading  like  the  Trivium  or  the 
Wedge  of  Casius,  or  simply  round  black  radiants,  like 
the  Luci  Ismenii. 

From  this  it  appears  that  the  lines  are  locally  de- 
pendent upon  the  general  topography  of  the  funda- 
mental features  of  the  surface.  For  some  reason  they 
connect  the  very  points  most  suggestive  of  intercom- 
munication. As  from  their  characteristics  it  is  per- 
fectly evident  that  the  lines  are  neither  rivers  nor 
cracks,  it  follows  that  such  a  communicating  habit  is 
of  the  most  telltale  character.  To  be  so  dissimilar  in 
kind  from  the  main  markings  and  yet  so  dependent 
upon  them,  hints  that  their  positioning  occurred  after 
the  formation  of  the  main  features  themselves.  We 
reach  thus  from  the  look  of  the  lines  and  their  location 
a  most  striking  deduction,  that  the  lines  are  not  coeval 
with  the  main  markings,  but  have  come  into  being  later 
and  with  reference  to  the  general  topography  of  the 
planet.  The  network  is  not  only  a  mesh  de  facto,  then, 
but  one  de  jure,  which,  subsequent  to  the  fashioning  of 
the  seas  and  continents  and  what  these  have  now  be- 
come, has  been  superposed  upon  them.. 


CHAPTER  XVII 

GEMINATION   OF   THE    CANALS 

T^RAUGHT  with  more  difficulty  than  the  detection 
-*-  of  the  lines  alone  is  the  next  discovery  made 
upon  the  disk :  the  recognition  of  pairs  of  lines  trav- 
ersing it. 

In  1879,  while  Schiaparelli  was  engaged  in  scrutiniz- 
ing the  strange  canali  he  had  discovered  on  the  planet 
the  opposition  before,  he  was  suddenly  surprised  to 
mark  one  of  them  double.  Two  closely  parallel  lines 
confronted  him  where  but  a  single  one  had  previously 
stood.  So  unaccountable  did  the  sight  seem,  that  he 
hesitated  to  credit  what  he  saw,  being  minded  to  at- 
tribute the  vision  to  illusion  of  some  sort  and  the  more 
so  that  it  was  not  renewed.  While  he  was  still  wonder- 
ing what  it  meant,  the  planet  parted  company  with  the 
Earth,  carrying  its  enigma  with  it. 

When  the  two  bodies  again  drew  near  to  one  another 
in  1882,  Schiaparelli  set  himself  to  watch  for  a  recurrence 
of  the  strange  phenomenon.  Before  long  it  came,  and 
more  bewilderingly  than  at  first;  for  not  one  canal 
alone,  but  a  score  of  them  now  showed  in  duplicate, 
each  presenting  to  his  astonished  gaze  twin  lines  per- 

192 


CHAP,  xvn     GEMINATION   OF  THE   CANALS  193 

fectly  matched  and  preserving  throughout  their  dis- 
tance apart.  Suspecting  diplopia  or  some  other  optical 
trick,  he  tried  various  eyepieces  to  a  test  of  the  cause 
but  to  no  change  in  the  effect.  The  twin  lines  con- 
tinued visible,  do  what  he  would,  insisting  on  their  own 
reality  in  spite  of  all  solicitation  to  merge.  How  cau- 
tious he  was  in  the  matter,  and  how  unwilling  at  first 
to  believe  the  evidence  of  his  eyes,  is  shown  by  the  care 
he  took  to  guard  against  deception.  It  was  not  until 
he  had  assured  himself  of  the  reality  of  the  phenomena 
that  he  believed  what  he  had  seen. 

It  so  chanced  that  my  first  experience  of  the  thing 
was  almost  equally  startling,  so  unexpected  was  it  and 
so  exceedingly  sharp  was  the  definition  at  the  time. 
It  was  in  an  autumn  early  twilight,  through  air  almost 
perfectly  still,  as  the  light  went  out  of  the  sky  and  the 
markings  on  the  planet  began  to  come  forth  that  the 
Phison  of  a  sudden  showed  in  duplicate  to  me,  clear-cut 
upon  the  disk,  its  twin  lines  like  the  rails  of  a  railway 
track  traversing  Aeria.  Not  more  vivid  do  those  of 
our  transcontinental  tracks  appear  as  one  sees  them 
stretching  off  into  the  distance  upon  our  Western 
plains.  More  impressive  was  the  sight  from  the  fact 
that  I  was  not  looking  for  it.  It  simply  suddenly 
stood  forth,  this  strange  parallelism  of  pencil  lines. 
My  surprise  matched  the  wonder  of  the  sight. 

Since  then  I  have  witnessed  it  several  hundred  times, 


194  MARS  AND   ITS   CANALS  CHAP,  xvn 

but  never  with  more  absolute  certainty  than  at  that 
first  fortunate  revelation.  To  this  distinctness  is  due 
the  amazement  it  then  aroused.  Not  simply  because 
of  its  surpassing  novelty,  but  for  the  insistence  with 
which  it  proclaimed  itself  was  the  effect  to  be  ascribed. 
Less  well  seen,  doubt  had  robbed  it  of  its  full  surprise. 
It  requires  as  a  rule  steady  definition  for  its  initial 
unmistakable  showing,  if  one  would  be  instantly  con- 
vinced. Except  for  such  it  is  not  usually  easy  to  the 
unpracticed,  though  often  discernible  to  the  expert 
after  it  has  once  been  seen.  But  that  it  is  real  no  one 
who  had  had  a  good  view  of  the  sight  could  doubt; 
still  less  after  the  experience  had  been  repeated  over 
and  over  again. 

What  appears  to  take  place  is  this:  where  pre- 
viously a  single  pencil-like  line  joined  two  well-known 
points  upon  the  disk,  twin  lines,  the  one  the  replica  of 
the  other,  stand  forth  in  its  stead.  The  two  lines  of  the 
pair  are  but  a  short  distance  apart,  are  of  the  same  size, 
of  the  same  length,  and  absolutely  equidistant  through- 
out their  course.  It  is  as  if  a  second  line  had  in  some 
way  been  mysteriously  added  to  the  first  since  the 
latter  was  last  seen  some  weeks  before.  This  in  a  word 
is  the  phenomenon,  technically  called  the  gemination 
of  the  canals,  which  has  since  its  discovery  called  forth 
so  much  comment.  It  is  not  in  reality  quite  as  simple 
or  as  sudden  as  it  seems,  but  this  was  the  way  in  which 


CHAP,  xvii     GEMINATION   OF  THE   CANALS  195 

the  phenomenon  was  first  seen  and  in  which  it  still 
continues  to  be  criticised. 

Self-assertive  of  reality,  the  double  lines  are  patently 
objective  to  him  who  is  fortunate  enough  to  see  them 
well.  Nevertheless  the  great  difficulty  of  detecting 
them,  and  the  still  greater  difficulty  of  conceiving  how 
such  things  can  be,  has  led  many  not  versed  in  the  sub- 
ject to  disbelieve  and  from  that  to  attempt  to  explain 
the  sight  as  illusory.  Scepticism  seeks  self-j ustification ; 
what  is  hard  of  acceptance  for  its  strangeness  begetting 
hypotheses  of  committed  error  which  find  easy  cre- 
dence for  their  comforting  conservatism.  Several 
such  have  in  consequence  been  propounded  to  account 
for  the  double  canals.  There  is  the  diplopic  theory 
which  credits  them  to  non-focusing;  the  interferential 
theory  which  would  make  them  optical  products  of  the 
telescope;  and  the  illusion  theory  which  would  have 
them  quite  simply  imaginary. 

Inasmuch  as  in  any  research  the  assurance  that  a 
phenomenon  is  real  is  the  first  point  about  it  to  be 
established,  it  is  a  scientist's  duty,  not  only  to  scan  the 
phenomena  with  jealous  care  to  that  end,  but  to  scru- 
tinize every  theory  which  would  seek  otherwise  to 
account  for  them  —  the  testing  such  being  only  second 
in  importance  to  observing  the  things  themselves. 
Accordingly  I  have  examined  each  of  the  optical  theo- 
ries that  have  been  advanced  and  critically  compared 


196  MARS   AND   ITS   CANALS  CHAP.  XVH 

what  they  assert  and  require  with  the  results  of  obser- 
vation. The  outcome  of  this  research  has  proved  as 
negativing  to  any  other  origin  for  the  double  canals 
than  reality  as  direct  observations  at  the  telescope  are 
positive  on  the  point.  To  show  this  I  shall  review 
each  in  its  consequences,  confronting  it  with  what  the 
telescope  has  to  say  on  the  subject ;  for  it  is  of  the  pith 
of  the  matter  that  the  reality  should  be  as  demon- 
strable on  demand  as  on  sight.  Furthermore,  I  shall 
do  this  before  embarking  on  the  general  account  of  these 
strange  things,  because  it  is  vital  to  any  interest  that 
one  should  be  assured  from  the  start  of  the  truth  of 
what  he  is  to  read.  The  preface  may  seem  to  him  ab- 
struse and  prosy,  but  it  will  introduce  him  to  some  curi- 
ous optical  properties  and  will  eventually  enhance  his 
concern  by  proving  to  him  that  what  reads  like  fiction 
is  all  the  more  wonderful  for  being  fact. 

/.    The  Diplopic  Theory 

Diplopia  is  the  property  of  seeing  double  with  one  eye. 
Surprising  as  it  sounds  it  is  an  effect  not  unknown  to 
students  of  optics,  though  it  usually  requires  training 
to  produce.  It  is  possible  only  when  the  eye  is  not 
focused  on  the  object,  and  is  not  always  possible  then. 
From  my  experiments  its  feasibility  seems  to  depend 
upon  whether  the  focus  be  beyond  or  before  what  it 
should  be.  If  the  eye  be  focused  for  a  point  beyond  the 


CHAP,  xvii     GEMINATION   OF  THE   CANALS  197 

object,  the  object  is  doubled,  if  for  a  point  this  side  of 
it,  the  latter  is  simply  blurred.  When  the  double  is 
formed,  the  amount  of  the  separation  of  the  two  images 
is  a  function  of  the  distance  the  focus  is  out.  The 
greater  the  discrepancy,  the  wider  apart  is  the  ensuing 
double.  Nor  does  the  image,  of  a  line,  for  example, 
stop  at  doubling.  After  a  certain  breadth  of  separation 
is  reached  a  third  line  appears,  bisecting  the  interval 
between  the  other  two.  With  yet  greater  widening 
the  third  line  itself  splits  into  a  pair  and  so  the  reso- 
lution goes  on.  In  my  own  experiments  I  have  gone 
so  far  as  to  suspect  a  fifth  line.  Far  from  being  uncon- 
scious, the  process  of  producing  the  phenomenon  is, 
with  some  people,  of  difficult  accomplishment.  Mr. 
Lampland,  for  instance,  of  the  Flagstaff  Observatory, 
to  whom  we  owe  the  first  photographing  of  the  canals, 
and  who  sees  the  doubles  of  Mars  without  difficulty, 
has  hitherto  found  diplopic  vision  an  impossible  feat. 
Even  with  the  most  practiced  diplopia  is  never  uncon- 
scious except  when  the  object  viewed,  as  a  micrometer 
wire,  has  nothing  to  locate  it  in  space.  Now,  the  di- 
plopic theory  of  the  double  canals  supposes  that  in  all 
cases  the  eye  of  the  observer  is  thus  unconsciously 
out  of  focus. 

To  this  method  of  their  manufacture  the  telescopic 
phenomena  prove  unamenable  on  five  counts. 

1.   Focusing  the  eye  on  an  object  is  now  a  reflex  ac- 


198  MARS  AND  ITS   CANALS  CHAP,  xvn 

tion,  so  automatic  has  it  become ;  in  consequence  one  is 
commonly  directly  conscious  when  an  object  is  not  in 
focus,  always  so  when  the  object  presents  detail.  Were 
such  not  the  case  we  should  never,  except  by  chance, 
see  anything  defined.  Observing  through  a  telescope, 
after  a  modicum  of  practice,  differs  in  no  respect  from 
observing  in  everyday  life.  Consequently,  that  an 
experienced  observer  should  not  know  his  business 
in  so  primary  a  matter  is  preposterous.  One  may  or 
may  not  believe  that  "the  undevout  astronomer  is 
mad, "  but  that  the  perpetually  unfocused  one  would 
be  is  beyond  debate. 

2.  Generically  unlikely,  the  failure  to  focus  is  here 
specifically  out  of  the  question.  For  the  observer  does 
not  use  the  canals  to  focus  on  for  the  simple  reason  that 
he  cannot.  Like  all  delicate  detail,  the  doubles  appear 
not  continuously  but  by  flashes  of  revelation,  according 
as  the  atmospheric  waves  permit  of  passage  undis- 
turbed. To  focus  on  them  would  be  next  to  impossible 
even  were  it  resorted  to  —  which  it  never  is.  By  the 
exponents  of  the  theory  this  important  fact  is  over- 
looked :  the  unforeseen  showing  of  the  canals  and  there- 
fore the  absolute  lack  of  complicity  of  the  eye  in  the 
matter.  What  one  focuses  on  is  the  look  of  the  main 
markings  of  the  disk.  Now,  to  suppose  an  observer 
systematically  out  in  his  perceptions  of  so  featureful 
a  planet  as  that  of  Mars,  so  that  he  does  not  know  when 


CHAP,  xvn     GEMINATION  OF  THE  CANALS  199 

he  sees  its  image  sharp,  implies  a  lack  of  knowledge 
of  astronomic  observation  in  the  supposer. 

3.  Study  by  the  writer  shows  the  width  of  a  given 
double  canal  to  be  constant  for  a  given  date.     Within 
the  errors  of  perception  or  recording  the  twin  lines  are 
always  at  the  same  epoch  the  same  distance  apart. 
The  greater  the  number  of  determinations  made,  the 
nearer  the  result  approaches  to  this  mean;  and  the 
greater  the  care  used  in  delineation,  the  less  each  value 
departs  from  it. 

Now,  if  the  thing  were  a  matter  of  mistaken  focusing, 
an  eye  could  not  be  thus  true  to  its  own  mistakes.  If 
it  were  out  in  its  focus  by  a  certain  amount  at  one  time, 
it  would  be  likely  to  be  out  by  a  different  amount  at 
another.  So  that  by  the  very  terms  of  its  making  a 
diplopic  double  would  be  sure  to  vary.  Indeed,  in 
laboratory  experiments  it  is  impossible  to  prevent  it. 
For  the  eye  rests  itself  automatically  by  change  of  focus, 
and  if  it  be  not  consciously  kept  awry  it  reverts  as  near 
to  the  true  focus  as  it  can  of  its  own  accord. 

4.  Diplopia  might  be  a  respecter  of  persons,  but  it 
certainly  could  not  be  one  of  canals.     For  a  given  ob- 
server it  must  be  objectively  general  in  its  application 
to  the  same  class  of  obj ects.    Consequently,  if  the  doub- 
ling were  diplopic,  all  canals  inclined  at  the  same  angle 
to  the  vertical  —  for  the  tilt  might  affect  the  result 
were  the  eye  astigmatic  —  should  be  similarly  affected. 


200  MAKS  AND   ITS   CANALS  CHAP,  xvn 

Parallel  canals  should  parallel  each  other's  action. 
With  the  Martian  doubles  this  is  not  the  case.  Of  two 
canals  similarly  inclined  the  one  will  be  double,  the 
other  not,  at  the  same  instant  and  under  conditions 
that  are  alike.  And  this  persistently.  For  gemina- 
tion is  an  attribute  of  certain  canals  and  never  of  others. 
At  a  given  season  of  the  Martian  year,  some  canals  are 
regularly  double,  some  invariably  single.  Night  after 
night  and  presentation  after  presentation  these  idiosyn- 
crasies are  preserved :  the  doubles,  always  pairs,  the 
single,  always  alone.  Nor  does  the  strength  of  the  line 
affect  the  action.  The  single  canals  are  some  of  them 
stronger,  some  of  them  weaker,  than  the  doubles  seen 
at  the  same  time. 

5.  If  of  diplopic  origin  the  mean  width  of  all  the 
doubles  should  be  the  same.  For  though  the  diplopic 
width  would  vary  for  a  given  canal  according  to  the 
moment,  a  sufficient  number  of  views  would  yield  a 
mean  width  which  would  be  the  same  for  all.  Tilt 
apart,  the  mean  width  of  one  canal  would  be  that  of 
another.  Among  Martian  doubles,  on  the  contrary, 
I  have  found  the  width  to  be  a  specific  property 
of  the  particular  canal.  Each  has  its  own  mean  width 
regardless  of  inclination,  and  this  individual  width 
differs  as  between  one  and  another  by  as  much  as  five 
to  two,  or,  if  we  consider  such  canals  as  the  Nilokeras 
I  and  II,  by  more  than  ten  to  two. 


CHAP,  xvn      GEMINATION   OF  THE   CANALS  201 

Any  one  of  these  five  points  is  fatal  to  the  theory; 
a  fortiori  all. 

//.    The  Interference  Theory 

From  the  wave  propagation  of  light  it  follows  that 
the  image  of  a  bright  line  made  by  a  lens  is  not  itself 
a  simple  bright  line  but  a  bright  band  flanked  by  alter- 
nate dark  and  bright  ones.  It  has,  therefore,  been  sug- 
gested that  a  bright  medial  line  is  here  concerned  and 
that  the  double  canal  is  the  first  of  its  dark  pair  of  out- 
riders. But  the  suggestion  does  not  bear  scrutiny. 

1.  It  presupposes  a  central  streak  brighter  than  the 
rest  of  the  disk  to  give  birth  to  the  twin  dark  lines. 
This  should  itself  be  visible  in  the  image ;  but  no  such 
bright  backbone  is  seen. 

2.  It  demands  a  perfectly  definite  width  of  separation 
for  a  given  aperture  —  which  is  not  that  observed. 

3.  It  makes  the  width  a  function  of  the  aperture, 
decreasing  as  this  increases  —  which  is  not  sustained 
by  observation.     Different  apertures  produce  no  effect 
on  the  widths  of  the  Martian  doubles,  as  the  writer  has 
shown  (Lowell  Observatory  Bulletin,  No.  5)  by  a  change 
of  aperture  from  twenty-four  to  six  inches. 

4.  Under  like  optical  conditions  the  optically  pro- 
duced doubles  would  be  all  of  a  width;  while  the  Mar- 
tian ones  show  idiosyncratic  widths,  each  peculiar  to 
itself. 


202  MAES  AND  ITS   CANALS  CHAP,  xvn 

///.    The  Illusion  Theory 

Known  also  as  the  Small  Boy  Theory  from  the  in- 
genuous simplicity  on  which  it  rests,  this  theory  attacks 
the  reality  of  the  doubles  by  questioning  that  of  the 
canals  en  bloc.  Because  some  boys  from  the  Green- 
wich (Reform  or)  Charity  School,  set  to  copy  a  canal- 
expurgated  picture  of  the  planet,  themselves  supplied 
the  lines  which  had  preceptorily  been  left  out,  the 
Martian  canals  have  been  denied  existence;  which  is 
like  saying  that  because  a  man  may  see  stars  without 
scanning  the  heavens,  therefore  those  in  the  sky  do  not 
exist.  As  to  the  instructions  the  boys  received  we  are 
left  in  the  dark.  It  looks  as  if  some  leading  questions 
had  unconsciously  been  put  to  them.  At  all  events, 
English  charity  boys  would  seem  to  be  particularly 
pliant  to  such  imagination,  for  when  Flammarion  re- 
tried the  experiment  with  French  schoolboys,  and  even 
inserted  spaced  dots  for  the  canals  in  the  copy,  not  a 
boy  of  them  drew  an  illusory  line. 

The  fact  is,  this  is  one  of  those  deceptive  half-truths 
which  is  so  much  more  deleterious  than  an  unmitigated 
mistake.  Under  certain  circumstances  it  is  quite  pos- 
sible to  perceive  illusory  lines,  due  either  to  shadings 
otherwise  unmarked  and  thus  synthesized  or  to  im- 
mediately precedent  retinal  impressions  transferred 
to  places  where  they  do  not  belong  by  rapid  motion 


CHAP,  xvir     GEMINATION   OF  THE   CANALS  203 

of  the  eye,  as  I  had  myself  discovered  before  the 
English  experiment  had  been  tried.  But,  as  I  have 
also  found  out,  these  effects  are  produced  only  at  the 
limit  of  vision,  and  in  that  limbo  of  uncertainty  the 
whole  art  of  the  observer  consists  in  learning  to  dis- 
tinguish the  true  from  the  false.  Strength  of  impres- 
sion, renewed  effect  in  situ,  and  a  peculiar  sense  of 
reality  or  the  reverse  enable  him  to  adjudge  the  two. 
More  experience  than  the  boys  possessed  would  have 
helped  them  to  part  the  sheep  from  the  goats.  But, 
furthermore,  and  fatally  to  the  theory  here  in  question, 
the  Martian  canals  when  well  seen  are  not  at  the  limit 
of  vision  as  its  framers  supposed,  but  well  within  that 
boundary  of  doubt ;  so  that  the  premise  upon  which  the 
whole  theory  rests  gives  way.  Under  good  atmospheric 
conditions  the  canals  are  comparable  for  conspicuous- 
ness  to  many  of  the  well-recognized  Fraunhofer  lines 
and  are  just  as  certainly  there. 

Thus  each  attempt  to  prove  the  doubles  non- 
objective  turns  out  when  specifically  examined  to  be  in- 
consistent with  the  facts.  With  the  assurance  of  their 
reality  thus  made  doubly  sure,  we  pass  to  consideration 
of  the  things  themselves. 


CHAPTER  XVIII 

THE    DOUBLE    CANALS 


T3IGHTLY  viewed,  no  more  subtle  tribute  could  be 
paid  to  the  remarkable  character  of  the  phenom- 
enon of  gemination  than  the  scepticism  with  which  it 
was  immediately  received  and  which  it  still  continues 
to  elicit.  That  the  sight  should  be  regarded  as  illusory 
speaks  for  its  surpassing  strangeness;  and  so  far  as 
oddity  goes  the  encomium  is  certainly  deserved.  Of 
the  bizarre  features  of  this  curiously  marked  disk, 
the  double  canals  were  at  the  time  of  their  discovery 
the  culmination,  and  though  things  stranger  still  if 
possible  have  since  been  seen  there,  it  is  not  wonderful 
that  doubt  should  still  incredulously  stare.  If  the  mere 
account  of  them  reads  like  romance,  to  see  them  is  an 
experience. 

Nothing  astronomical  that  I  have  ever  seen  has  been 
so  startlingly  impressive  as  my  first  view  of  a  double 
canal.  Even  in  narration  the  thing  justifies  its  effect. 
For  a  double  canal  consists  of  a  pair  of  twin  dark  fila- 
ments, perfectly  parallel  throughout  their  course  and 
inclosing  between  them  ground  of  the  same  ochre 'sh 

204 


CHAP,  xvni  THE    DOUBLE   CANALS  205 

cast  as  that  which  lies  without.  Only  on  occasion  is 
this  tint  of  their  midway  departed  from,  and  then  only 
toward  a  darkening,  never  toward  a  lightening  of  it. 
Except  for  appearing  paired,  the  lines  resemble  pre- 
cisely the  usual  single  canals.  In  length  they  vary 
from  a  few  hundred  to  a  few  thousand  miles,  while  in 
width  each  component,  for  narrowness,  hardly  permits 
of  definite  ascription. 

Compared  for  strength  with  the  usual  canal  the  lines 
of  a  double  seem  to  hold  on  the  average  an  intermediate 
position  between  the  larger  and  the  smaller  of  the  single 
canals  so  far  detected.  Owing,  however,  to  the  massed 
effect  of  the  pair  by  reason  of  their  closeness,  they  have 
an  advantage  in  showing  over  the  singles  of  two  to  one. 
And  this  renders  them  among  the  most  conspicuous  and 
important  meshes  of  the  canal  network. 

Like  the  single  canals,  they  vary  in  strength  with  the 
Martian  time  of  year;  at  certain  seasons  developing 
into  heavy  pencil  lines  and  at  others  fading  away  to  the 
merest  gossamers,  only  just  discernible  like  cobwebs 
stretched  across  the  face  of  the  planet. 

Although  the  individual  constituent  lines  vary  in 
aspect  and  never  rise  at  their  most  to  cognizable 
breadth,  the  distance  parting  their  centres,  or  the  width 
of  the  double,  is  quite  measurable.  The  only  difficulty 
in  the  way  of  its  determination  lies  in  the  absence  of  a 
procurable  unit  small  enough  to  mete  it.  The  usual 


206  MAES   AND  ITS  CANALS  CHAP,  xvm 

spider-threads  of  the  micrometer  are  colossal  in  com- 
parison with  these  filaments  and  present  a  standard 
only  analogic  at  best.  Nevertheless,  by  means  of  the 
finest  threads  that  could  be  got,  estimates  of  the  dis- 
tance between  the  pairs  were  made  at  Flagstaff  in  1905, 
and  the  results  agree  as  closely  as  the  means  permit 
with  those  got  by  measurement  of  the  doubles  as 
depicted  in  the  drawings. 

Of  what  they  look  like,  the  following  illustrations 
give  a  fair  idea,  only  that  instead  of  being  more  geo- 
metrically   regular     in     the 
drawing  than  in  reality  the 
**i^ii,     n  \\     fact  is  the  other  way.     Free- 
nlF  \    hand   draftsmanship  at   the 

telescope  is  incapable  of  ren- 
dering their  ruled  effect.  No 
railway  metals  could  be  laid 
down  with  more  precision. 

Martian  doubles.  Ag  t()  their  ^  th(J  f0llowing 

figures  derived  from  a  typical  double  canal,  the  Phison, 
give  some  conception.  This  great  artery  of  inter- 
communication between  the  Sabaeus  Sinus  and  the 
Nilosyrtis  is,  roughly  speaking,  2250  miles  long;  the 
distance  between  the  centres  of  the  two  constituents 
is  about  130  miles,  and  each  line  is  perhaps  20  miles 
in  breadth,  when  at  its  maximum  strength.  The 
pair  follow,  apparently,  the  arc  of  a  great  circle  from 


CHAP,  xvm  THE  DOUBLE   CANALS  207 

the  Portus  Sigaeus  on  the  Mare  Icarium  to  the  Pseboas 
Lucus  in  latitude  40°  north.  The  Portus  Sigaeus  con- 
sists of  two  little  nicks  in  the  coastline,  looking  like 
the  carets  one  makes  in 
checking  off  items  down  a 
list,  if  the  space  between 
the  down  and  up  strokes 
were  then  filled  in;  the 
Pseboas  Lucus,  on  the  other 
hand,  is  a  large  round  dot 
like  a  small  ink  spot.  To 

these  tWO  differently  appear-       Martian  doubles  (corroborating 

the  above). 

ing  spots,  the  twin  lines  of 

the  Phison  behave  differently.  While  each  line  leaves 
centrally  its  own  caret  of  the  Portus  Sigaeus  at  the 
south,  at  the  north  each  touches  peripherally  the 
Pseboas  Lucus,  on  the  east  and  west  sides  respectively, 
the  two  thus  just  holding  the  Lucus  between  them. 
In  position  the  lines  are  invariable,  though  in  visibility 
not.  Sometimes  only  one  is  seen,  sometimes  both  show 
faintly,  and  sometimes  both  are  conspicuously  strong. 
The  delicacy  of  the  observations  by  which  this  detail 
was  established  is  second  only  to  its  importance.  It 
destroys  at  a  stroke  all  possibility  of  diplopic  un- 
reality, since  were  that  the  fact  the  Pseboas  Lucus 
should  be  doubled,  which  it  is  not.  At  the  same  time 
it  opens  vistas  into  the  true  construction  of  the 


208  MARS   AND   ITS   CANALS  CHAP,  xvm 

things  themselves,   at  present  more  suggestive  than 
satisfactory. 

In  the  great  circle  character  of  its  course  the  Phison 
is  quite  normal.  The  majority  of  the  double  canals 
pursue  the  like  method,  ^  running  straight  over  the 
surface  from  one  point  to  another,  the  constituents 
remaining  equidistant  throughout.  But  such  forth- 
rightness  of  direction,  though  the  rule,  is  not  with- 
out exceptions.  The  Thoth-Nepenthes,  for  example, 
sweeps  round  in  a  seemingly  continuous  curve  to  the 
west-southwest  from  the  Aquae  Calidae  to  the  Lucus 
Moeris  like  some  mighty  bow  perpetually  bent.  Never- 
theless its  lines  are  no  less  careful  for  all  their  curving 
to  keep  their  distance  from  one  end  to  the  other  of  their 
course.  The  quality  of  being  paired  rises  superior  to 
change  of  direction. 

ii 

Now,  the  first  point  to  be  noticed  about  the  doubles 
is  that  bilateralism,  or  the  quality  of  being  double, 
is  not  a  universal  trait  of  the  canals,  either  actually  or 
potentially;  it  is  not  even  a  general  one.  Out  of  the 
four  hundred  canals  seen  at  Flagstaff,  only  fifty-one 
have  at  any  time  displayed  the  quality;  that  is,  one 
eighth  roughly  of  the  whole  number  observed.  This 
point  is  most  important ;  for  the  fact  is  of  itself  enough 
to  disprove  any  optical  origin  for  the  phenomenon. 
The  characteristic  of  doubling  so  confidently  ascribed 


CHAP,  xvni  THE   DOUBLE   CANALS  209 

by  those  who  have  not  seen  it  to  general  optical  or  ocular 
principles  proves  thus  the  exception,  not  the  rule,  with 
the  canals,  and  by  so  doing  disowns  the  applicability 
of  any  merely  optical  solution.  We  shall  encounter 
many  more  equally  prohibitive  bars  to  illusory  expla- 
nation before  we  have  done  with  the  doubles,  but  it  is 
interesting  to  meet  one  in  this  manner  at  the  very 
threshold  of  the  subject. 

On  the  other  hand,  the  characteristic  when  possessed 
is  persistent  in  the  particular  canal,  in  posse  if  not  in  esse. 
Once  shown  by  a  canal,  that  canal  may  confidently 
be  looked  to  at  a  proper  time  to  disclose  it  again. 
In  short,  bilateralism,  or  the  state  of  being  dual,  is  an 
inherent  attribute  of  the  individual  canal,  as  idiosyn- 
cratic to  it  as  position  and  size. 

The  catalogue  of  canals  possessing  this  property, 
so  far  as  they  have  been  detected  at  Flagstaff  to  date, 
number  fifty-one  if  we  include  in  the  list  wide  parallels 
like  the  Nilokeras  I  and  II.  Eight  of  these  were  ob- 
served in  1894;  nineteen  more  were  added  in  1896, 
making  twenty-seven ;  in  1901  the  total  was  raised  to 
thirty;  in  1903  to  forty-eight;  and  in  1905  to  fifty-one. 
Arranged  by  years  they  are  tabulated  below,  where  the 
numeral  to  the  left  registers  for  each  its  first  recording 
and  the  position  held  by  it  in  the  list.  The  starred 
canals  much  exceed  the  others  in  width,  and  possibly 
denote  a  different  phenomenon. 


210 


MARS   AND  ITS   CANALS 


CHAP.   XVIII 


DATE                    CONFUSED 

DATE 

CONFUSED 

1894 

1900-1 

1.  Ganges 

Phison 

Dis  S. 

2.  Nectar 

Euphrates 

Boreas 

3.  Euphrates 

Hiddekel 

Cerberus  S. 

4.  *Nilokeras  I 

Amenthes 

Jamuna 

and  II 

Cerberus  N. 

Pyramus 

5.  Phison 

Cyclops 

Laestrygon 

6.  Asopus 

Ganges 

7.  Jamuna 

28.  Deuteronilus 

8.  Typhon 

Sitacus 

Adamas 

1896-7 

29.  Djihoun 

Ganges              Typhon 

Gihon 

Euphrates        Avernus  S. 

30.  Is 

Phison 

9.  Lethes 

1903 

Jamuna 

Djihoun 

Typhon 

10.  Dis  S. 

Hiddekel 

Orontes 

11.  Titan 

Phison 

12.  Laestrygon 

Euphrates 

13.  Tartarus 

31.  Protonilus 

14.  Cocytus 

Gihon 

15.  Sitacus 

32.  Marsias 

16.  Amenthes 

Amenthes 

17.  Adamas 

Laestrygon 

18.  Cerberus  N. 

Cyclops 

19.  Cerberus  S. 

Gigas 

20.  Cyclops 

*Nilokeras  I 

21.  Gelbes 

and  II 

22.  Erebus 

Ganges 

23.  Avernus  N. 

Deuteronilus 

24.  Gigas 

33.  Pierius 

25.  Alander 

34.  Callirrhoe 

26.  Gihon 

Jamuna 

27.  Hiddekel 

Sitacus 

CHAP.  XVIII 


THE   DOUBLE   CANALS 


211 


DATE 
1903 

35.  Astaboras  S. 

36.  Nar 

37.  Chaos 

38.  Aethiops 

39.  Hyblaeus 

40.  Eunostos 

41.  Thoth 

42.  Nepenthes 

43.  Triton 

44.  Pyramus 

45.  Fretum  Anian 

46.  Vexillum 
Lethes 
Cerberus  S. 

47.  Nilokeras  I 
Cerberus  N. 

48.  Tithonius 

1905 

Nilokeras 
Hiddekel 
Djihoun 
Sitacus 
Phison 
Euphrates 


CONFUSED 


Ganges 
Chrysorrhoas 


DATE 
1905 

Amenthes 
Vexillum 
Astaboras  S. 
Adamas 
Cyclops 
Cerberus  S. 
Cerberus  N. 
Tartarus 

49.  *Propontis 
Gigas 
Gihon 
Nepenthes 
Thoth 
Laestrygon 

50.  Polyphemus 
Deuteronilus 
Triton 
Eunostos 
Tithonius 
Callirrhoe 
Pyramus 
Nar 
Protonilus 

51.  Naarmalcha 


CONFUSED 


In  spite  of  possessing  the  property  of  pairing,  a  canal 
may  not  always  exhibit  it.  To  the  production  of  the 
phenomenon  the  proper  time  is  as  essential  as  the 
property  itself.  So  far  as  a  primary  scanning  or  first 
approximation  is  capable  of  revealing,  a  canal  will  be 
single  at  one  Martian  season  and  double  at  another. 


212  MARS   AND   ITS   CANALS  CHAP,  xvm 

Thus  these  canals  alternated  in  their  state  to  Schia- 
parelli  and  for  the  earlier  of  his  own  observed  oppo- 
sitions to  the  writer.  In  consequence  Schiaparelli 
deemed  gemination  a  process  which  the  canal  periodi- 
cally underwent.  Three  stages  in  the  development 
were  to  him  distinguishable :  the  single  aspect,  a  short 
confused  aspect,  and  the  clearly  dual  one. 

In  the  single  state. the  canal  remained  most  of  the 
time.  It  then  underwent  a  chrysalid  stage  of  confu- 
sion to  emerge  of  a  sudden  into  a  perfect  pair.  Fur- 
thermore, he  noted  the  times  at  which  the  pairing  took 
place,  to  the  formulating  of  a  law  in  the  case  —  de- 
rived from  the  observations  of  more  than  one  opposition. 
His  law  was  that  the  gemination  occurred,  on  the  aver- 
age, three  months  (ours)  after  the  summer  solstice 
of  the  northern  hemisphere,  lasted  four  to  five  months, 
then  faded  out  to  begin  afresh  one  month  after  the  vernal 
equinox  of  the  same  hemisphere  and  continue  for  four 
months  more.  Expressed  in  Martian  seasonal  chro- 
nology, the  periods  would  be  about  half  as  long.  At 
certain  times  then  the  most  pronounced  specimens  of 
doubles  showed  obstinately  single,  while  the  periodic 
metamorphosis  that  transformed  them  into  duplicates 
was  timed  to  the  changes  of  the  planet's  year.  Gemi- 
nation, then,  was  a  seasonal  phenomenon. 

Advance  in  our  knowledge  of  the  phenomenon  since 
Schiaparelli's  time,  while  still  showing  the  thing  to  be 


CHAP,  xvin  THE   DOUBLE   CANALS  213 

of  seasonal  habit,  has  changed  our  conception  of  it. 
It  now  appears  that  in  some  cases  certainly,  and  pos- 
sibly in  all,  the  dual  aspect  is  not  a  temporary  condition, 
but  the  differing  pronouncement  of  a  permanent  state, 
the  fact  of  gemination  so  called  being  confined  to  a 
filling  out  of  what  is  always  skeletonly  there.  As  the 
canals  have  come  to  be  better  seen,  the  three  stages  of 
existence  have  in  some  cases  become  recognizable  as 
only  different  degrees  in  discernment  of  an  essential 
double  condition;  the  single  appearance  being  due  to 
the  relative  feebleness  of  one  of  the  constituents  and  the 
confused  showing  to  the  weakness  of  both,  which  are 
then  the  more  easily  blurred  by  the  air  waves.  In  cer- 
tain canals  the  last  few  oppositions,  1901,  1903,  and 
1905,  have  disclosed  this  unmistakably  to  be  the  case, 
as  with  the  Phison  and  Euphrates,  for  example.  With 
them  the  double  character  has  been  continuously  visible, 
appearing  not  only  when  by  Schiaparelli's  law  it  should, 
but  at  the  times  when  it  should  not ;  only  on  these  latter 
occasions  it  was  harder  to  see,  whence  the  reason  it  was 
previously  missed.  So  that  further  scrutiny,  while  in 
no  sense  discrediting  the  earlier  observations,  has  ex- 
tended to  them  some  modification,  and  disclosed  the 
underlying  truth  to  be  the  varying  visibility,  the  thing 
itself,  except  for  strength  in  part  or  whole,  persisting 
the  same.  Improvement  in  definition  has  lowered  the 
see-level  to  revelation  of  continuous  presence  of  the 


214  MARS  AND  ITS   CANALS  CHAP,  xvm 

dual  state.  It  is  only  on  occasion  that  the  improvement 
is  sufficient  for  the  thing  when  at  its  feeblest  to  loom 
thus  above  the  horizon  of  certainty;  yet  at  such  mo- 
ments of  a  rise  in  the  seeing  it  is  enough  to  allow  it 
to  be  glimpsed.  Thus  it  fared  with  the  Adamas  at  the 
opposition  of  1903,  with  the  Gigas,  and  with  many 
another  in  years  gone  by.  Separation  has  come  with 
training  and  generally  in  the  case  of  the  wider  doubles, 
which  leads  one  to  infer  that  ease  of  resolution  is  largely 
responsible  for  assurance  of  the  permanency  of  the  dual 
state.  Perplexing  exceptions,  however,  remain,  so 
that  it  is  possible  at  present  only  to  predicate  the 
principal  of  most  of  the  double  canals  but  not  of  all. 
Leaving  the  exceptions  out  of  account  for  the  moment, 
we  pass  to  those  general  characteristics  which  are  in- 
timately linked  with  what  has  just  been  said. 

Inasmuch  as  the  act  of  getting  into  a  state  antedates 
the  fact  of  being  there,  it  is  logical  to  let  the  description 
of  the  first  precede.  An  account  of  the  process  of  gemi- 
nation may  thus  suitably  come  before  that  of  its  result. 

Flux,  affecting  the  double  canals  in  whole  or  part, 
is  the  cause  of  the  apparent  gemination.  According 
as  the  flux  is  partitive  or  total  is  a  single  or  a  dual  state 
produced.  At  the  depth  of  its  inconspicuousness  the 
canal  may  cease  to  be  visible  at  all ;  this  occurs  when 
both  lines  fade  out.  On  the  other  hand,  the  one  line 
may  outfade  the  other,  and  we  are  presented  with  a 


CHAP,  xvm  THE   DOUBLE   CANALS  215 

seemingly  single  canal,  at  this  its  minimum  showing. 
In  such  seasons  of  debility  the  one  line  may  appear  and 
the  other  not,  or  occasionally  the  other  show  and  the  one 
not,  according  to  the  air  waves  of  the  moment.  It  is 
at  these  times  that  the  double  simulates  a  single  canal, 
and  unless  well  seen  and  carefully  watched  might  easily 
masquerade  successfully  as  such.  The  Hiddekel  in  the 
depth  of  its  dead  season  is  peculiarly  given  to  this  al- 
ternately partitive  presentation.  As  the  flux  comes  on, 
one  or  both  lines  feel  it.  If  one  only  we  are  likely  to 
have  a  confused  canal ;  if  both,  a  difficult  double.  The 
strength  of  the  lines  increases  until  at  last  both  attain 
their  maximum,  and  the  canal  stands  revealed  an  un- 
mistakable pair,  the  two  lines  paralleling  one  another 
in  appearance  as  in  position. 

At  the  canal's  maximum  and  minimum  the  equality 
of  its  two  constituents  is  chiefly  to  be  remarked,  though 
it  occurs  on  other  occasions  as  well.  But,  what  is  signifi- 
cant, when  the  two  differ  it  is  always  the  same  one  that 
outdoes  its  fellow.  It  may  be  the  right-hand  twin  in 
one  pair,  the  left-hand  one  in  another ;  but  whichever 
it  be,  for  the  particular  canal  its  preeminence  is  in- 
variable. It  is  this  canal  which,  except  for  adventitious 
help  or  hindrance  from  the  air-waves,  alone  shows 
when  the  double  assumes  the  seemingly  single  state. 
We  may  therefore  call  it  the  original  canal,  the  other 
being  dubbed  the  duplicate.  In  some  cases  it  has  been 


216 


MARS   AND   ITS   CANALS 


CHAP     XVIII 


possible  to  decide  which  is  which.  It  might  seem  at 
first  sight  as  if  this  point  should  always  be  ascertainable. 
But  the  determination  is  more  dilemmic  than  appears, 
not  from  any  difficulty  in  seeing  the  canal,  but  from  the 
absence  of  distinguishing  earmark  at  its  end.  In  a 
long  stretch  of  commonplace  coast,  the  precise  point  of 
embouchure  of  a  solitary  canal  cannot  be  so  certainly 
fixed  as  to  be  decisive  later  between  two  which  show 
close  together  in  the  same  locality.  It  is  only  where 
some  landmark  points  the  canal's  terminal  that  the 
problem  admits  of  definite  solution.  This  telltale 
tag  may  be  a  bay  like  the  Margaritifer  Sinus,  or  double 
gulfs  like  the  Sabaeus  Sinus,  or  portions  of  a  marking 
not  too  large  to  permit  of  partitive  location  like  the 
Mare  Acidalium,  or  a  canal  connection  like  the  Tacazze 
which  prolongs  the  one  line  and  not  the  other.  In  these 
and  similar  instances  the  two  lines  become  capable  of 
identification,  and  in  such  manner  have  been  found 
those  comprised  in  the  following  list: — 


DOUBLE  CANAL 

ORIGINAL  LINE 

DATE  OF 

ASCERTAINMENT 

Phison 

The  Eastern 

1894 

Euphrates 

The  Western 

1894 

Titan 

The  Western 

1896 

Hiddekel 

The  Eastern 

1896 

Gihon 

The  Western 

1896 

Gigas 

The  Northwestern 

1896 

Djihoun 

The  Western 

1901 

Laestrygon 

The  Eastern 

1903 

Nilokeras  I  and  II 

The  Northern 

1903 

Astaboras 

The  Southern 

1903 

Jamuna 

The  Eastern 

1905 

Ganges 

The  Western 

1905 

CHAP,  xvin  THE   DOUBLE   CANALS  217 

In  this  list  of  originals  the  canals  stand  chrono- 
logically marshaled  according  to  date  of  detection. 
The  Phison  and  Euphrates  were  the  first  to  permit  of 
intertwin  identification  in  1894,  while  the  Jamuna  and 
Ganges  were  the  last  to  be  added  to  the  column  in  1905. 
The  list  is  not  long,  though  the  time  taken  to  compile  it 
was.  In  the  case  of  the  Ganges  and  the  Jamuna,  for 
example,  although  suspected  for  some  time  on  theo- 
retic grounds,  it  was  only  at  the  opposition  just  passed 
that  the  fact  was  observationally  established.  In 
his  Memoria  V,  Schiaparelli  has  a  list  of  similar  detec- 
tion, and  if  the  present  list  be  compared  with  his,  the 
two  having  been  independently  made,  the  concordance 
of  the  result  will  prove  striking,  corroborative  as  it  is 
of  both.  For  the  necessary  observations  are  very 
difficult. 

Having  thus  realized  the  original  by  means  of  its 
superior  showing,  and  then  identified  it  by  its  position, 
it  is  suggestive  to  discover  that  the  duplicate  betrays 
its  subordinate  character,  not  only  by  its  relative  insig- 
nificance, but  by  its  secondary  position  as  well.  The 
original  always  takes  its  departure  from  some  well- 
marked  bay,  seemingly  designated  by  nature  as  a  de- 
parture-point, or  from  a  caret  belonging  clearly  to  itself ; 
the  adjunct,  on  the  other  hand,  leaves  from  some  neigh- 
boring undistinguished  spot,  as  in  the  case  of  the  addi- 
tional Djihoun,  or  makes  use  of  a  neighbor's  caret,  as  in 


218  MAES   AND  ITS   CANALS 


CHAP.    XVIII 


the  case  of  the  second  Phison  and  the  supplementary 
Euphrates.  In  either  case  it  plays  something  of  the 
part  of  an  afterthought ;  and  yet  the  postscript  when 
finished  reads  as  an  integral  part  of  the  letter.  An 
example  will  serve  to  make  the  connection  evident  while 
leaving  the  character  of  the  connection  as  cryptic  as 
ever. 

In  the  long  stretch  of  Aerial  coastline  bounding  the 
Mare  Icarium,  which  sweeps  with  the  curve  of  a  fore- 
time beach  from  the  Hammonis  Cornu  to  the  tip  of 
the  Edom  Promontory,  there  stand  halfway  down  its 
far-away  seeming  sea-front  two  little  nicks  or  indenta- 
tions. Even  in  poor  seeing  they  serve  to  darken  this 
part  of  the  coast  while  in  good  definition  they  come  out 
as  miniature  caret-like  bays.  They  are  the  Portus 
Sigaei,  and  mark  the  spots  where  the  Phison  and  the 
Euphrates  respectively  leave  the  coast.  About  four 
degrees  apart,  the  eastern  makes  embouchure  to  the 
original  Phison,  the  western  to  the  original  Euphrates, 
and  each  in  some  mysterious  manner  is  associated  not 
only  in  position  but  in  action  with  the  canal  itself. 
In  the  single  state  each  canal  leaves  the  Mare  from 
this  its  own  caret,  the  Phison  proceeding  thence  north- 
east down  the  disk,  the  Euphrates  nearly  due  north, 
so  that  starting  four  degrees  apart  at  the  south  they 
are  forty  degrees  asunder  at  their  northern  termini. 
Clearly  at  these  latter  points  they  are  not  even  neigh- 


CHAP,  xvm  THE  DOUBLE   CANALS  219 

bors,  and  except  for  the  accident  of  close  approach  at 
their  other  ends  have  nothing  in  common  anywhere. 
And  yet  when  gemination  takes  place  a  curious  thing 
occurs:  each  borrows  its  neighbor's  terminal  as  de- 
parture-point for  its  own  duplicate  canal.  Having  thus 
got  its  base  the  replica  proceeds  to  parallel  its  own 
original  canal  without  the  least  reference  to  the  other 
canal  whose  own  caret  it  has  so  cuckoo-wise  appro- 
priated. What 
the  Phison  thus 
does  to  the  Eu-  - 

phrates,  the  Eu- 
phrates  returns 
the  compliment 
by  doing  to  the  /f^' 

Phison.     In  this 

manner  is  produced  an  interrelation  which  suggests, 
without  necessarily  being,  an  original  community  of 
interest ;  suggests  it  on  its  face  and  yet  appears  to  be 
rather  of  the  nature  of  an  adaptation  to  subsequent 
purposes  of  a  something  aboriginally  there. 

That  such  latter-day  appropriation  is  the  fact  is 
clearly  hinted  by  the  behavior  of  another  understudy 
of  an  original  canal,  in  this  case  the  duplicate  of  the 
Djihoun,  which  in  consequence  of  the  position  of  its 
original  finds  no  neighboring  embouchure  already 
convenient  to  its  use.  The  single  or  original  Djihoun 


220  MAES  AND  ITS  CANALS  CHAP,  xvm 

leaves  the  tip  of  the  needle-pointed  Margaritifer  Sinus, 
which  serves  a  like  end  to  the  Oxus  and  the  Indus,  both 
single  canals.  The  Sinus  is  itself  a  single  bay,  and  so 
large  that  for  many  degrees  its  shores  on  both  sides  con- 
verge smoothly  to  their  sharp  apex.  Because  of  this 
probably,  the  coast  in  the  immediate  neighborhood  is 
without  canal  connection,  no  canal  being  known  along 
either  side  till  one  reaches  the  Hydraotes  at  the  Aroma- 
ticum  Promontorium,  which  marks  the  western  limit 
of  the  gulf.  The  consequence  is  that  when  the  Dji- 
houn  doubles,  the  duplicate  canal,  not  having  any  ter- 
minus ready  to  its  hand,  has  to  make  one  for  itself 
by  simply  running  into  the  Margaritifer  Sinus,  some 
distance  up  its  eastern  side.  It  thus  advertises  its  ad- 
junctival  character,  and  at  the  same  time  the  general 
fact  that  a  neighbor's  terminus,  though  used  from  prefer- 
ence, when  convenient,  is  not  an  essential  in  the  process. 
Gemination  occurs  of  its  own  initiative,  but  is  condi- 
tioned by  convenience. 

Whether  one  canal  shows  thus  to  the  exclusion  of  the 
other,  or  whether  both  stand  so  confused  as  not  to  be 
told  apart,  the  fact  remains  that  the  double  is  not  always 
recognizable  as  such.  If  we  turn  to  the  list  of  the 
doubles  on  page  222,  we  shall  note  that  the  same  canals 
were  not  always  seen  in  the  dual  condition  at  successive 
oppositions.  Some,  indeed,  are  so  emphatically  of  the 
habit  as  to  appear  year  after  year  in  a  paired  state,  but 


CHAP,  xvm  THE  DOUBLE    CANALS  221 

others  are  not  so  constant  to  their  possibilities.  Now, 
when  it  is  remembered  that  at  different  oppositions  we 
view  Mars  at  diverse  seasons  of  its  tropical  year,  we  see 
that  this  means  that  the  phenomenon  is  seasonal; 
and  furthermore  that  its  exhibition  depends  upon  the 
canal's  position.  Gemination,  like  the  showing  or  non- 
showing  of  the  single  canal,  is  conditioned  by  the  place 
of  the  canal  upon  the  planet. 

in 

Turning  from  such  generic  characteristics  to  more 
specific  traits,  the  first  thing  to  strike  an  attentive  ob- 
server is  that  the  doubles  differ  in  width ;  that  they  are 
not  mensurably  alike  in  the  property  they  hold  in  com- 
mon of  being  paired.  In  some  the  twin  lines  are  ob- 
viously farther  apart  than  in  others,  and  the  relation 
persists  however  repeated  the  observations.  Of  two 
doubles  the  one  will  always  surpass  its  fellow.  This 
contrasted  individuality  first  struck  me  in  the  Phison 
and  the  Euphrates;  and  from  the  first  moment  at 
which  these  doubles  showed  as  such.  The  Phison  pair 
seemed  perceptibly  the  narrower  of  the  two.  A  like 
distinction  was  evident  at  the  next  opposition  and 
the  next;  in  fact,  at  every  succeeding  one  to  the 
present  day.  Nor  was  the  recognition  of  the  fact 
confined  to  me.  If  we  turn  to  Schiaparelli's  Memoriae 
we  shall  find  that  that  master  had  registered  the  same 


222 


MAES  AND   ITS   CANALS 


CHAP.  XVIII 


idiomatic  width  for  the  two  canals  from  first  to  last 
throughout  his  long  series  of  records.  The  observation 
thus  made  proved  to  apply  to  each  and  all  of  these 
curious  twins. 

Diversity  in  width  for  different  doubles  appears 
plainly  in  drawings  where  more  than  one  double  is 
depicted.  As  an  example,  two  drawings  are  here 
given  in  the  text,  made,  the  one  on  July  13,  1905,  X15°, 
and  the  other  on  July  20,  X313°.  In  them  the  Phison, 
Euphrates,  Djihoun,  and  Thoth  appear  contrasted  as 
unmistakably  as  either  of  them  does  with  the  single 
canals  apparent  at  the  same  time.  That  this  drawing 
is  typical  is  borne  out  by  all  the  best  measures  of  the 
several  doubles  as  seen  at  successive  oppositions,  and 
marshaled  in  the  subjoined  list.  How  truly  individual 
the  quality  is  stands  proved  by  the  relative  values  in 
different  years  which  are  even  more  accordant  than  the 
absolute  ones. 

The  canals  were  :  — 


WIDTH 

1903 

1905 

MEAN 

1.    Phison    
2.     Euphrates  

3.5 
40 

3.4 

42 

3.4 
4  1 

3.  *Protonilus 

2  8 

2  0 

2  4 

4.     Deuteronilus 

2  2 

2  4 

2  3 

Poor. 


CHAP.   XVIII 


THE   DOUBLE   CANALS 


223 


WIDTH 

1903 

1905 

MEAN 

5.     Pierius   
6.     Callirrhoe   
7.  *Hiddekel     
8    *Gihon 

2.5 
2.5 
3.8 
3  9 

*2.1 
4.9 
4  9 

2.5 
2.3 
4.3 
4  4 

9.     Djihoun      

20 

1  9 

1  9 

10.     Sitacus  

3  8 

*3  3 

3  6 

11.     Jamuna  
12      Ganges 

4.5 
5  0 

5  2 

4.5 
5  1 

13      Nilokeras  I  and  II 

11  0 

11  7 

11  3 

14.     Nilokeras  I      
15.     Gigas      
16      Laestrygon 

2.3 
3.5 
2  2 

2.3 
3.5 
2  2 

17      Cerberus  N 

40 

40 

18.    Cerberus  S  
19.     Cyclops  
20.     Nar    ... 

4.0 
2.9 
2  6 

*2.2 
2.0 

4.0 
2.6 
2.3 

21      Fretum  Anian 

2  8 

28 

22      Aethiops 

3  3 

3  3 

23.     Eunostos     
24.     Lethes    
25.     Marsias  

2.8 
2.9 
3  2 

— 

2.8 
2.9 
3.2 

26      Hyblaeus 

3  o 

3.0 

27      Amenthes 

3  2 

3  5 

3.3 

28      Thoth 

2  8 

2  3 

2.5 

29.     Nepenthes  

2.8 

2.3 

2.5 

30.     Triton    .     . 

2  7 

*2.3 

2.5 

31      Pyramus 

2  9 

*2.0 

2.5 

32      Astaboras  S 

3  2 

3.1 

3.1 

33.     Tithonius    
34.     Vexillum     
35.     Tartarus               

2.6 
3.5 

2.2 
2.9 
2.7 

2.4 
3.2 

2.7 

Poor. 


224  MARS  AND  ITS   CANALS  CHAP,  xvm 

Here  we  have  widths  ranging  from  eleven  degrees  to 
two.  The  widths  given  are  those  when  the  canal  was  at 
or  sufficiently  near  its  full  strength,  and  are  measured 
from  the  centres  of  the  constituents.  We  notice  .two 
points:  the  agreement  of  the  same  canal  with  itself 
and  its  systematic  disagreement  with  others.  But 
what  is  especially  to  the  point,  if  we  compare  the  values 
found  at  successive  oppositions,  we  find  that  for  differ- 
ent canals  the  values  agree  in  their  difference.  This 
shows  that  each  of  these  values  is,  in  most  cases  if  not 
in  all,  a  norm  for  that  particular  canal;  a  value  dis- 
tinctive of  it  and  to  which  it  either  absolutely  or  rela- 
tively conforms.  In  other  words,  the  width  of  the 
gemination  is  a  personal  peculiarity  of  the  particular 
canal,  as  much  an  idiosyncrasy  of  it  as  its  position  on 
the  planet. 

Two  general  classes  may  be  distinguished ;  those  up 
to  about  five  degrees  in  width  apart  and  those  above 
this  figure.  Whether  such  very  widely  separated  lines 
as  go  to  make  up  the  second  class,  such  as  the  Nilokeras 
I  and  II,  constitutes  a  double  is  a  debatable  point. 
Schiaparelli  thought  they  did,  and  so  classed  them. 
To  me  it  did  not  at  first  occur  so  to  consider  them, 
and  in  some  instances,  such  as  the  Helicon  I  and 
II,  later  observations  seem  to  justify  the  omission. 
With  the  Nilokeras  I  and  II  the  outcome  seems  the 
other  way.  The  reasons  for  distrust  of  a  physical  rela- 


CHAP,  xviii  THE   DOUBLE   CANALS  225 

tion  between  the  constituents  is  not  so  much  the  dis- 
tance separating  them,  nor  any  lack  of  parallelism,  as 
the  self-sufficient  manner  in  which  they  show  alone. 
Even  this,  however,  tends  to  be  recognized  in  the  nar- 
rower pairs  as  they  come  to  be  better  seen.  It  may 
be  that  width  alone  is  wholly  competent  to  selective 
showing.  For  the  farther  apart  two  lines  are  on  the 
planet,  the  more  opportunity  is  afforded  the  air  waves 
to  disclose  the  one  without  the  other,  a  relative  revela- 
tion which  is  constantly  happening  to  detail  in  different 
parts  of  the  disk.  As  long  as  any  doubt  exists  of  a 
physical  community  of  interest,  it  seems  best  to  dis- 
tinguish such  possibly  merely  parallel  canals  by  suffixed 
numerals. 

Of  this  class  of  doubles  is  the  Nilokeras  I  and  II. 
So  wide  is  it  that  Mr.  Lampland  succeeded  in  photo- 
graphing it  as  such,  the  two  constituents  showing  well 
separated,  and  if  it  prove  a  true  double  it  will  be  the 
first  Martian  double  to  leave  its  impress  on  a  sensitive 
plate.  Although  separated  by  four  hundred  miles  of 
territory,  the  two  lines  are  parallel  so  far  as  observa- 
tion can  detect,  which,  of  course,  is  not  so  very  easy 
with  the  lines  so  far  apart.  In  the  country  between 
one  crosswise  canal  certainly  lies,  the  Phryxus,  and 
much  shading  thus  far  unaccounted  for.  Recent  dis- 
coveries, however,  point  to  the  cause  of  such  shading  as 
lines  imperfectly  seen.  For  in  some  cases  the  lines 
Q 


226  MARS  AND  ITS   CANALS  CHAP,  xvm 

have  actually  disclosed  themselves,  and  warrant  us  in 
believing  that  it  is  only  imperfect  seeing  that  keeps  the 
others  hid.  Of  the  pair  the  Nilokeras  I  is  itself  double, 
curiously  reproducing  what  sometimes  is  seen  in  the 
case  of  double  stars,  one  of  whose  components  turns 
out  to  be  itself  a  binary.  The  second  line  of  the  Niloke- 
ras I  lies  close  to  its  primary  on  the  north,  and  was  on 
the  only  occasion  of  its  detection  the  merest  of  gossa- 
mers, while  the  Nilokeras  I  itself  stood  out  strong  and 
dark.  Thus  do  these  Martian  details  increase  and  mul- 
tiply in  intricacy  the  better  the  seeing  brings  them  out. 

In  the  case  of  the  other  doubles,  the  doubles  proper 
so  to  speak,  there  is  every  indication  of  a  physical  bond 
between  the  pair.  What  that  bond  may  be  is  another 
matter  and  seems  to  be  of  different  divulging,  according 
to  the  particular  instance.  At  one  end  of  the  subject, 
both  as  the  widest  of  these  doubles  and  one  of  the  most 
important,  stands  the  Ganges.  The  components  of 
the  canal  are  5°.l  apart.  This  great  width,  joined  to 
the  fact  of  scant  extension,  gives  the  canal  a  stocky 
aspect,  its  breadth  being  but  one  sixth  of  its  length. 
Its  width  draws  attention  to  it  while  the  phenomena 
it  exhibits  intrigue  curiosity. 

As  early  as  the  first  opposition  of  my  observations 
in  1894,  the  canal,  as  it  underwent  the  process  of 
doubling,  showed  phases  of  peculiarity.  It  was  first 
caught  by  me  as  a  double  over  toward  the  terminator, 


CHAP,  xvm  THE   DOUBLE   CANALS  227 

or  fading  edge  of  the  disk ;  then  as  it  was  brought  nearer 
the  centre  by  the  gaining  upon  the  longitudes,  showed 
as  a  broad  swath  of  shading  of  a  width  apparently  equal 
to  any  it  later  exhibited.  In  this  appearance  it  con- 
tinued for  some  months,  and  then  in  October  began  to 
show  a  clarification  toward  the  centre.  Once  started, 
the  lightening  of  its  midway  advanced  till  at  last,  on 
November  13,  it  stood  out  an  unmistakable  double,  the 
two  lines  standing  where  the  edges  of  the  swath  had 
previously  been.  Had  the  observations  here  been  all 
that  one  could  wish,  the  method  of  gemination  would 
have  been  certain  and  of  great  interest.  Unfortunately, 
the  observations  left  much  to  be  desired,  and  those  re- 
peated in  1896-1897  and  1901  were  of  like  doubtful- 
ness. A  period  of  swarthy  confusion  preceded  the 
plainly  dual  state,  but  whether  the  double  simply 
clarified  or  widened  as  well  it  was  not  possible  to  assure 
one's  self.  That  the  canal  exhibited  plainly  the  effects 
of  seasonal  development  was  as  unmistakable  as  the 
steps  themselves  were  open  to  ambiguity.  In  1903 
the  canal  was  at  its  minimum  and  hardly  to  be  made 
out.  It  seemed  then  to  show  an  actual  change  in 
width  coincident  with  alteration  of  visibility.  But 
this,  too,  could  not  be  predicated  with  certainty.  It 
was  also  surmisable  that  the  westernmost  line  was 
the  one  from  which  the  development  proceeded. 

In  1905  much  more  was  made  out  about  it,  training 


228  MAES  AND  ITS  CANALS  CHAP,  xvm 

in  the  subject  and  increased  proximity  of  the  planet 
contributing  to  the  result.  It  now  became  clear  to 
me  that  the  canal  did  develop  from  the  western  side ; 
for  the  western  edge  made 
a  dark  line  of  definite  bound- 
ary from  which  shading  pro- 
ceeded to  the  eastern  side, 
where  it  faded  almost  imper- 
ceptibly off  with  no  denned 
line  to  mark  its  limit.  That 
this  shading  gradually  dark- 

Peculiar  development  of  the 

Ganges.  ened  was   evident,  but  that 

when  it  could  be  seen  at  all  it  extended  to  the  ex- 
treme limit  of  the  eventual  double,  restricted  the 
character  if  not  the  fact  of  an  actual  widening.  At 
this  opposition,  too,  the  canal  passed  through  its 
period  of  minimum  visibility  and  was  then  seen, 
whenever  it  could  be  caught,  as  a  confused  swath  of 
full  width.  In  the  case  of  this  canal,  then,  a  widen- 
ing in  the  sense  of  a  bodily  separation  of  two  lines 
seems  inadmissible.  On  the  other  hand,  the  gradual 
darkening  of  the  swath,  and  especially  the  advance  of 
the  darkening  from  the  western  side,  points  to  an 
interesting  process  there  taking  place. 

-At  the  opposite  end  of  the  series  stands  the  Djihoun. 
As  the  Ganges  is  the  widest  of  the  instantly  impressive 
doubles,  so  the  Djihoun  is  the  narrowest  the  eye  has  so 


CHAP,  xviii  THE   DOUBLE   CANALS  229 

far  been  able  to  make  out.  Only  two  fifths  of  the 
width  of  the  Ganges  pair,  this  slender  double  is  very 
nearly  at  the  limit  of  resolvability.  So  well  propor- 
tioned are  its  lines  to  the 
space  between  them,  how- 
ever, that  in  ease  of  recogni- 
tion it  surpasses  many  wider 
pairs.  In  form,  too,  it  is  dis- 
tinctive, turning  by  a  grace- 
ful curve  the  trend  of  the 
Margaritifer  Sinus  into  the 

LUCUS     IsmeniuS.        With     its      DJihoun'  the  narrowest  double. 

fundamental  branch  —  the  northern  of  the  two  —  it 
joins  what  is  evidently  the  main  line  of  the  Proto- 
nilus  —  also  the  northern  one  —  to  the  Margaritifer 
Sinus's  tip. 

It  differs  from  the  Ganges  in  some  other  important 
particulars  besides  width.  In  its  case  no  band  of  shad- 
ing distinguishes  it  at  any  time.  It  has  always  been 
two  lines  whenever  it  has  been  seen  other  than  as  a 
single  penciling;  the  only  confusion  about  it  being 
evidently  our  own  atmosphere's  affair.  These  two 
lines,  furthermore,  have  showed,  within  the  errors  of 
observation,  always  the  same  distance  apart.  So  that 
not  only  no  change  of  intercommunication  between  the 
lines  but  no  change  in  their  places  apparently  occurs. 

Between  these  extremes  in  width,  two  hundred  miles 


230  MAES  AND   ITS  CANALS  CHAP,  xvm 

more  or  less  for  the  Ganges  and  seventy-five  miles  for 
the  Djihoun,  the  distance  parting  the  pairs  of  most  of 
the  double  canals  lies.  From  3°  to  3°. 2  on  the  planet 
may  be  taken  as  that  of  the  average ;  the  degrees  denot- 
ing latitudinal  ones  on  the  surface  of  Mars,  the  length 
of  which  is  equal  to  thirty-seven  of  our  English  statute 
miles. 

Most  of  the  canals  conform  apparently  to  the  type 
of  the  Djihoun  rather  than  to  that  of  the  Ganges. 
Careful  consideration  of  them  fails  to  find  any  increase 
or  decrease  of  distance,  between  the  pairs  of  the  same 
canal  at  different  tunes,  which  cannot  be  referred  to 
errors  inevitable  to  observation  of  such  minute  detail. 
In  short,  the  double  is  made  by  the  addition  of  a  sec- 
ond line  in  a  particular  position  and  not  by  a  growth 
out  to  it  of  a  line  coincident  to  begin  witn  with  the  first. 

I  have  said  that  the  average  width  between  the  two 
lines  of  the  doubles  was  about  3°.  It  must  not  be 
supposed  that  this  average  width  denotes  anything 
more  than  an  average ;  or,  in  other  words,  that  it  de- 
notes anything  in  the  nature  of  a  norm.  The  remark 
is  important  in  view  of  a  suggestion  which  I  have  heard 
made  that  we  have  here  a  system  based  on  fundamental 
Martian  units,  in  which,  or  in  multiples  of  which,  the 
dimensions  of  the  canals  are  implicitly  expressed.  Such, 
however,  does  not  seem  to  be  the  case.  In  some  in- 
stances, indeed,  we  have  certain  evidence  to  the  con- 


CHAP,  xvni  THE  DOUBLE   CANALS  231 

trary  and  that  the  width  of  the  double  is  conditioned 
solely  by  antecedent  place.  The  Phison  and  Euphrates 
offer  a  case  in  point.  These  two  important  arteries 
in  duplicate  leave,  as  we  saw,  from  two  carets  in  the 
Mare  Icarium,  the  Portus  Sigaei,  held  in  common  ten- 
ancy by  both.  Each  pair  then  proceeds  down  the  disk 
inclined  at  its  own  particular  angle  to  the  meridian  in 
order  to  reach  by  a  great  circle  course  a  certain  spot; 
the  Pseboas  Lucus  in  one  case,  the  Luci  Ismenii  in  the 
other.  As  one  of  these  angles  is  thirty-five  degrees 
while  the  other  is  only  three,  they  must,  from  the 
circumstances  of  their  setting  out,  have  not  only 
different  widths,  but  widths  determinately  different  in 
advance,  since  each  is,  roughly  speaking,  foreshortened 
by  the  degree  of  divergence  from  the  meridian.  The 
one,  therefore,  must  be  about  four  degrees  to  the  other's 
something  less  than  three  and  a  half.  This  is  what  they 
actually  are  as  determined  by  measurement  from  obser- 
vation. That  the  calculated  value  agrees  with  that 
found  from  observation  helps  certify  to  a  community 
of  starting-points,  but  it  completely  does  away  with 
comprehensive  design  in  the  question  of  their  widths. 
For  if  the  one  were  so  settled,  the  other  could  not  be. 
Indeed,  the  next  example  seems  to  deny  it  to 
both.  This  example  occurs,  too,  not  far  away  from 
the  scene  of  the  first,  in  the  twin  bays  of  the  Sabaeus 
Sinus,  from  which  depart,  mutatis  mutandis,  the 


232  MAKS  AND  ITS   CANALS  CHAP,  xvm 

double  Hiddekel  and  the  two  Gihon.  These  twin 
gulfs  bear  so  little  imprint  of  being  other  than  natural 
formations,  that  they  have  been  universally  and  very 
likely  quite  rightly  taken  for  such  ever  since  Dawes 
discovered  them  in  1859,  long 
before  things  like  canals  were 
dreamed  of.  It  is  strange 
that  when  the  Hiddekel  and 
the  Gihon  were  found  by  me 
to  be  double  in  1897,  with  a 
branch  of  both  leading  from 
each  bay,  the  connection  be- 

The    Sabaeus  Sinus,   embouchure  A,  ,-11  ,      i 

for  the  double    Hiddekel    and    twe611  thg   Sceptically  SCOUted 

Gihou-  doubles  and  the  thoroughly 

believed-in  bays  should  have  been  apparent.  For  to 
link  a  ghost  to  materiality,  if  it  does  not  discredit 
the  materiality,  serves  to  substantialize  the  ghost. 
Furthermore,  it  shows  that  in  this  case  neither  the 
one  double  nor  the  other  can  have  had  its  width 
engineered  on  any  preconceived  scale,  unless  the 
twin  bays  be  themselves  so  accounted  for.  So  that 
it  seems  useless  to  seek  for  cryptic  standards  in  the 
canals  or  to  think  to  find  them  a  measure  of  value 
from  the  fact  of  their  being  a  medium  of  exchange. 

A  third  instance  of  the  same  thing  in  the  case  of  the 
Ganges  and  the  Jamuna  was  proved  at  the  last  oppo- 
sition after  having  long  been  suspected  without  my 


CHAP,  xviii  THE   DOUBLE   CANALS  233 

being  able  to  make  sure  of  it.  These  instances,  taken 
in  connection  with  the  wide  range  of  values  in  the 
widths  presented  by  different  canals,  serve  to  show 
that  the  distance  between  the  twin  lines  is  an  individual 
characteristic  of  the  particular  canal,  and  further  to 
point  to  its  cause,  in  some  cases  certainly  and  possibly 
in  all,  as  topographical.  The  duplicate  line  makes  a 
convenience  of  a  neighbor,  and  suits  its  distance  from 
its  fellow  to  friendly  feasibility.  To  cut  a  'canal '  to 
conform  to  the  country  seems  logical  if  not  obliga- 
tory, and  quite  in  keeping  with  the  nomenclature  of 
the  subject;  but  here  the  starting-point  appears  to  be 
the  only  thing  considered  —  the  canal  once  safely 
launched  being  left  to  shift,  or  rather  not  shift,  for  itself. 

IV 

Topography  thus  introduced  to  our  notice  for  its 
effect  on  the  breadth  of  the  doubles  proves  upon  inspec- 
tion to  be  of  extended  application  to  the  whole  sub- 
ject. Examined  for  position  these  canals  turn  out  to 
have  something  to  say  for  themselves  bearing  on  the 
question  of  their  origin  and  office. 

With  regard  to  position,  probably  the  first  query  to 
suggest  itself  to  an  investigator  to  ask  is  of  the  direc- 
tion in  which  they  run.  Is  there  a  preponderance  mani- 
fest in  them  for  one  direction  over  another  ?  Do  they 
show  an  inclination  to  the  vertical,  to  the  horizontal, 


234  MARS   AND  ITS   CANALS  CHAP,  xvm 

or  to  some  tilt  between  ?  To  answer  this  we  may  box 
the  compass,  and  taking  the  four  cardinal  points  with 
the  twelve  next  most  important  points  between  for 
sectional  division  segregate  the  doubles  according  to 
their  individual  trend.  As  we  have  no  means  of  deter- 
mining in  which  sense  any  direction  is  to  be  taken,  —  if 
indeed  it  is  not  to  be  taken  alternately  in  each,  —  we 
get  eight  compartments  into  one  or  the  other  of  which 
all  the  doubles  must  fall.  This  they  do  in  the  following 
manner :  — 

S.  &  N.,  Laestrygon,  fFretum  Anian,  Aethiops,   Amenthes, 

Titan,  fDis,  fls 7 

S.  S.  E.  &  N.  N.  W.,  fGihon,  Ganges,  J  Tithonius,  Euphrates, 

Adamas 5 

S.  E.  &  N.  W.,  fEunostos,  Triton,  Tartarus,  Naarmalcha  .  4 
E.  S.  E.  &  W.  N.  W.,  fAstaboras,  Typhon,  fPierius  .  .  3 
E.  &  W.,  fNar,  fProtonilus,  *Propontis,  J  Nectar,  fCocytus, 

tChaos, 6 

E.  N.  E.  &  W.  S.  W.  fDeuteronilus,  fCallirrhoe,  t  Cerberus  X., 

Cerberus  S.,  fSitacus,  t  Erebus 6 

N.  E.  &  S.  W.,  tDjihoun,  *Nilokeras  I  &  II,  fAvernus,  fNe- 

penthes,  Gigas,  fAlander,  Polyphemus,  tGelbes,  tMar- 

sias,  tPyramus,  fNilokeras  I,  Asopus  .  ...  12 
N.  N.  E.  &  S.  S.  W.,  Jamuna,  Phison,  fHyblaeus,  Cyclops, 

Lethes,  fThoth,  fVexillum,  fHiddekel  .  .  _8 

51 

No  conclusively  marked  preponderance  for  one  direc- 
tion over  another  manifests  itself  by  this  partition- 
ment.  Nevertheless,  a  certain  trend  to  the  east  of 

*Wide  canals.  f  Northern  hemisphere  exclusively, 

t  Southern  hemisphere  exclusively. 


CHAP,  xvui  THE  DOUBLE    CANALS  235 

north,  as  against  the  west  of  north,  is  discernible. 
More  than  twice  as  many  doubles  run  northeast  and 
southwest  or  within  forty-five  degrees  of  this  as  do 
similarly  northwest  and  southeast,  there  being  twelve 
of  the  latter  and  twenty-six  of  the  former.  That  this 
seems  to  mean  something  the  nearly  equal  pairing  of 
quadrantal  points  goes  to  show.  Thus :  — 

N.  &  S.  and  E.  &  W.  inclined  canals  number    .         .       7  +    6  =  13 

N.  N.  E.  &  S.  S.  W.  and  E.  S.  E.  &  W.  N.  W.  in- 
clined canals  number     .         .         .         .         .         .       8+3  =  11 

N.  E.  &  S.  W.  and  S.  E.  &  N.  W.  inclined  canals 

number 12  +   4  =  16 

E.  N.  E.  &  W.  S.  W.  and  N.  N.  W.  &  S.  S.  E.  in- 
clined canals  number     6+5  =  11 

33     18     51 

a  fairly  equable  division  in  direction.  A  trend  to  the 
westward  would  be  given  a  particle  descending  from 
the  north  to  the  equator  by  the  planet's  rotation,  thus 
turning  it  southwesterly;  and  one  to  the  west  to  a 
particle  travelling  equatorwards  from  the  south,  turn- 
ing it  northwesterly.  As  the  doubles  lie  in  the  northern 
hemisphere,  either  in  whole  or  part,  to  the  extent  of 
93  %,  this  might  account  for  the  preponderating  tilt  to 
the  east  of  north  and  west  of  south  exhibited  by  them. 
It  would  correspond  with  the  lines  of  flow. 

To  see  whether  this  be  so  we  will  take  only  those 
double  canals  that  lie  exclusively  in  the  northern  and 
southern  hemispheres  respectively,  and  note  those  in 


236  MAES   AND   ITS   CANALS  CHAP,  xvm 

the  former  that  trend  to  the  west  of  south  as  against 
those  that  run  to  the  east  of  it,  and  vice  versa  in  the 
southern.  In  the  northern  the  proportion  of  the 
westerly  to  the  easterly  ones  is  17  to  4 ;  in  the  southern, 
1  to  0  the  other  way. 

Of  those  whose  course  is  common  to  both  hemispheres 
we  find  for  the  ratio  of  the  southwesterly  to  the  south- 
easterly 8  to  7.  But  the  proportion  o'f  the  course  of 
these  canals  in  the  two  hemispheres  is  on  the  side  of 
this  same  ratio. 

From  their  direction  we  now  pass  to  consideration 
of  their  distribution  in  longitude.  It  appears  that 
some  meridians  are  more  favored  than  others.  The 
hemisphere  which  has  the  Syrtis  Major  for  centre  is 
more  prolific  in  them  than  its  antipodes.  From  longi- 
tude 80°  to  200°  there  are  ten  doubles,  from  200°  to 
320°  twenty-four,  and  from  320°  to  80°  seventeen;  or, 
roughly,  in  the  proportion  of  2,  5,  and  3.  That 
this  distribution  means  anything  by  itself  is  doubtful ; 
it  is  much  more  likely  to  be  a  general  topographical 
consequence  of  their  distribution  in  another  direction, 
which  proves  to  be  highly  significant  and  which  we 
shall  now  expose  —  that  of  latitude. 

If  we  separate  the  surface  into  zones,  each  ten  degrees 
wide,  and  count  the  doubles  found  traversing  in  whole 
or  part  the  several  zones,  we  find  the  following  arrange- 
ment :  — 


CHAP.  XVII 


THE   DOUBLE   CANALS 


237 


fc,                    OK     Q 

«  w 

2  15 

fc 

2 

'£  ^  "^ 

DOUBLE  CANALS  OF  MARS 

£H     ^ 

ft)   O    <» 

ARRANGED  ACCORDING  TO  LATITUDE 

1     S 

0*  4 

a22 

i 

^ 

* 

* 

Between  30°  S.  and  20°  S.     Tithonius,    Nectar,  Laes- 

trygon 

2 

3 

Between  20°  S.  and  10°  S.     Jamuna,    Ganges,  Gigas, 

Laestrygon,      Cyclops, 

Titan,  Tartarus,  Poly- 

phemus, Tithonius 

7 

9 

Between  10°  S.  and  0°           Jamuna,   Ganges,  Gigas, 

Laestrygon,      Cyclops, 

Cerberus    S,   Aethiops, 

Lethes,  Amenthes,  Tri- 

ton,   Phison,    Euphra- 

tes,   Titan,    Tartarus, 

Adamas,  Typhon,  Vex- 

illum,    Asopus,     Naar- 

malcha,  Polyphemus   . 

15 

20 

Between  0°  and  10°  N.           Gihon,  Djihoun,  Jamuna, 

Ganges,    Gigas,    Laes- 

trygon,    Cerberus     N, 

Cyclops,    Cerberus     S, 

Eunostos,       Aethiops, 

Lethes,  Amenthes,  Tri- 

ton, Nepenthes,  Phison, 

Euphrates,        Sitacus, 

Hiddekel,        Tartarus, 

Adamas,   Asopus,    Ty- 

phon, Vexillum,  Cocy- 

tus,    Is,    Avernus    N, 

Naarmalcha,    Polyphe- 

mus       

21 

29 

238 


MAKS  AND   ITS   CANALS 


DOUBLE  CANALS  OF  MARS 
ARRANGED  ACCORDING  TO  LATITUDE 

AT  OPPOSITION  OF 
1903  ALONE 

AT  ALL  OPPOSITIONS 
SO  FAR  OBSERVED 
AT  FLAGSTAFF 

Between  10°  N.  and  20°  N.    Gihon,  Djihoun,  Jamuna, 

Nilokeras    I    and    II,1 

Nilokeras     I,    Ganges, 

Gigas,  Eunostos,  Aethi- 

ops, Lethes,  Amenthes, 

Thoth,  Astaboras,  Phi- 

son,  Sitacus,  Euphrates, 

Hiddekel,  Adamas,  Aso- 

pus,    Gelbes,    Avernus 

N,  Erebus,  Naarmalcha, 

Vexillum,  Is,  Dis 

18 

26 

Between  20°  N.  and  30°  N.    Gihon,  Djihoun,  Jamuna, 

Nilokeras  I  &  II  ,'  Nilo- 

keras I,  Alander,  Hyb- 

laeus,    Lethes,    Amen- 

thes,   Thoth,    Sitacus, 

Astaboras,     Vexillum, 

Phison,         Euphrates, 

Hiddekel,         Adamas, 

Eunostos,       Aethiops, 

Gelbes,      Avernus     N, 

Naarmalcha,  Is  . 

17 

23 

Between  30°  N.  and  40°  N.    Deuteronilus,      Alander, 

Nar,   Marsias,  Fretum 

Anian,          Amenthes, 

Thoth,  Vexillum,  Phi- 

son,  Euphrates,  Hidde- 

kel, Adamas,  Eunostos, 

Djihoun,  Gihon,  Nilo- 

keras I,  Chaos,  Gelbes, 

Aethiops,  Naarmalcha, 

12 

20 

Very  wide  and  possibly  not  of  the  same  class. 


CHAP.    XVIII 


THE   DOUBLE   CANALS 


239 


DOUBLE  CANALS  OF  MARS 
ARRANGED  ACCORDING  TO  LATITUDE 


B    B 

II 

O  co 


in 

!sj 


Between  40°  N.  and  50°  N.     Fretum  Anian,  Pyramus, 
Protonilus,    Propontis1 

Between  50°  N.  and  60°  N.     Callirrhoe,  Fretum  Anian, 
Pierius 

Between  60°  N.  and  63°  N.     Pierius,  Callirrhoe   . 


From  this  tabulating  of  them  it  is  apparent  that  the 
doubles  are  practically  confined  to  the  zones  within 
forty  degrees  of  the  equator.  Only  7  ^  of  them  straggle 
farther  north  than  this,  while  above  63°  north  latitude 
and  35°  south  latitude  there  are  none.  Such  a  distri- 
bution is  not  in  proportion  to  the  areas  of  the  zones, 
which  though  diminishing  toward  the  poles  do  so 
at  no  such  rate.  The  surface  included  between  the 
equator  and  40°  of  latitude  is  65  56  of  the  hemisphere, 
whereas  the  fraction  of  the  number  of  doubles  found 
there  is  93^.  The  doubles  are,  then,  an  equatorial 
feature  of  the  planet,  confined  to  the  tropic  and  tem- 
perate belts. 

To  perceive  the  tropical  character  of  the  doubles  in 
another  way  we  have  but  to  consider  the  zonal  dis- 
tribution of  the  single  canals.  Unlike  the  former  the 

1  Very  wide  and  possibly  not  of  the  same  class. 


240  MAES  AND  ITS   CANALS  CHAP,  xvm 

latter  do  not  thin  out  as  one  advances  toward  the  poles ; 
since  in  the  arctic  regions  single  canals  bemesh  the  sur- 
face as  meticulously  as  elsewhere.  It  is  only  that  they 
there  replace  the  doubles ;  or,  not  to  put  the  cart  before 
the  horse,  it  is  the  doubles  that  in  part  replace  the  singles 
in  the  tropics.  And  that  this  arrangement  has  some- 
thing physical  behind  it  by  way  of  cause  is  curiously 
shown  by  two  canals,  the  Arnon  and  the  Kison,  which 
are  neither  of  the  one  kind  nor  yet  the  other,  but  a 
cross  between  the  two.  For  the  Arnon  and  the  Kison 
are  convergent  doubles;  the  two  lines  of  the  Kison 
leaving  a  common  point  at  the  edge  of  the  polar  cap 
and  separating  as  they  travel  south,  while  the  two 
Arnon  take  up  and  continue  the  divergence,  connect- 
ing at  last  with  the  parallel  pair  of  the  Euphrates. 
These  canals  thus  make  transition  between  the  true 
doubles  and  the  true  singles,  and  may  be  looked  upon 
as  endowed  with  the  potentialities  of  both.  •  From 
their  association  with  the  double  Euphrates,  it  is  clear 
that  the  transition  between  the  two  forms  is  not  only 
formal  but  physical,  and  that  the  stopping  of  the  dual 
condition  at  the  fortieth  parallel  is  not  the  outcome 
of  chance. 

It  may  occur  to  the  thoughtful  that  the  doubles  ap- 
pear confined  to  the  more  tropical  portions  of  the  planet 
because  of  a  better  presentation  of  those  zones,  the 
reader  supposing  the  planet  to  be  seen  axised  perpen- 


CHAP.  XVIH  THE   DOUBLE   CANALS  241 

dicularly  to  the  plane  of  sight,  as  geographies  represent 
the  earth's  globe.  The  supposition,  however,  is  errone- 
ous. We  sometimes  see  the  planet  so,  but  more  often 
not.  Such  is  the  tilt  of  the  Martian  axis  to  the  plane 
of  the  Martian  ecliptic  that  the  different  zones  are 
rarely  seen  on  an  even  keel,  so  to  speak,  their  aspects 
shifting  totally  from  one  opposition  to  another.  What 
shows  in  mid-disk  on  one  occasion  may  be  forty-eight 
degrees  removed  from  it  at  another,  a  distance 
amounting  to  three-quarters  of  the  way  from  apparent 
equator  to  apparent  pole. 

Thus  the  double  canals  are  for  some  intrinsic  reason 
equatorial  features  of  the  planet  as  opposed  to  polar 
ones.  And  this  not  simply  because  of  greater  space 
there.  Duality  is  a  result  of  conditions  intrinsic  to 
the  several  localities.  Wliat  the  cause  may  be  is  re- 
lated to  the  character  of  the  things  themselves,  which 
we  shall  later  consider.  For  the  moment  we  may  note 
that  the  fact  disposes  quietly  of  the  diplopic  theory 
of  their  manufacture.  For,  for  diplopic  doubles  to 
show  such  respect  for  the  equator  would  betoken  a 
courtesy  in  them  to  be  commended  of  Sydney  Smith. 

But  this  is  not  their  only  geographic  bias.  In  addi- 
tion to  not  being  partial  .to  the  poles,  the  double  canals 
show  a  certain  exclusiveness  toward  the  dark  areas 
generally.  Not  only  do  they  avoid  the  arctic  and  ant- 
arctic zones  entirely,  but  they  largely  shun  the  blue- 


242  MAES  AND  ITS  CANALS  CHAP,  xvm 

green  regions.  In  these  but  two  suspicions  of  doubles 
occur,  in  the  Aonium  Sinus,  although  single  canals 
there  are  as  numerous  as  anywhere  else  on  the  planet. 

Nevertheless,  although  they  avoid  running  through 
them,  they  run  from  them  in  a  manner  that  is  marked. 
Proceeding  from  the  great  diaphragm  are  no  less  than 
28  out  of  the  53  doubles.  Connecting  directly  with 
these  are  17  more;  while  the  remaining  8  are  also  asso- 
ciated through  the  intermediarism  of  dark  areas,  the 
Solis  Lacus  and  the  Trivium. 

In  like  relation  to  dark  regions,  they  are  limited  on 
the  north  by  the  Mare  Acidalium,  the  Propontis,  the 
Wedge  of  Casius  and  their  interconnecting  bands,  the 
Pierius,  Callirrhoe,  Helicon.  In  this  manner  do  they 
form  a  broad  girdle  round  the  planet's  waist,  leaving 
the  polar  extremities  bare. 


CHAPTER  XIX 

CANALS   IN  THE   DARK   REGIONS 

[EVENTEEN  years  after  the  recognition  of  the 
canals  in  the  light  regions  occurred  another  im- 
portant event,  the  discovery  of  a  similar  set  in  the  dark 
ones.  The  detection  of  these  markings  in  the  dark 
areas  was  a  more  difficult  feat  than  the  perceiving  of 
those  in  the  light,  and  in  consequence  was  later  accom- 
plished. Also  was  it  one  where  recognition  came  by 
degrees. 

I  have  previously  pointed  out  what  this  discovery 
did  for  the  seas  —  nothing  less  than  the  taking  away 
of  their  character  in  a  generally  convincing  manner. 
To  one  who  had  carefully  considered  the  matter, 
the  seas  had  indeed  already  lost  it,  as  was  shown  in 
Chapter  X,  but  to  those  who  had  not  these  canals 
presented  a  very  instant  proof  of  the  fact. 

From  such  not  wholly  supererogatory  service  they 
went  on  to  furnish  unlooked-for  help  in  other  directions. 
Their  discovery  showed  in  the  first  place  that  no  part 
of  the  planet's  surface  was  free  from  canal  triangulation. 

But  it  did  more  than  this.  For  these  canals  in  the 
dark  regions  left  the  edge  of  the  'continents'  at  the 

243 


244  MARS  AND  ITS   CANALS  CHAP,  xix 

very  points  where  the  canals  of  the  light  regions  entered 
them,  which  fact  proved  for  them  a  community  of 
interest  with  the  latter.  Such  continuation  was  highly 
significant,  since  it  linked  the  two  together  into  a  single 
system,  compassing  the  whole  surface  of  the  planet. 
Starting  from  the  places  where  the  light-region  canals 
come  out  upon  the  great  girdle  of  seas  that  stretches  all 
round  the  planet,  most  of  the  new  canals  headed  toward 
the  passes  between  the  islands  south,  as  nearly  pole- 
wards as  circumstances  of  local  topography  would  per- 
mit. In  the  broader  expanses  of  the  Syrtis  Major  and 
the  Mare  Erythraeum,  besides  main  arteries  others 
went  to  spots  in  their  midst  after  the  same  fashion 
as  those  of  the  light  regions.  These  spots  differed  in 
no  way  apparently  from  their  fellow  oases  elsewhere. 
From  a  spot  in  the  centre  of  the  Syrtis  three  great  lines 
thus  traveled  south:  the  Dosaron,  heading  straight 
up  the  Syrtis  on  the  meridian  till  it  struck  the  northern- 
most point  of  Hellas;  the  Orosines,  inclined  more  to 
the  right,  passing  through  the  dark  channel  to  the  west 
of  that  land  and  so  proceeding  south;  and  lastly  the 
Erymanthus  turning  eastward  till  it  brought  up  finally 
at  the  Hesperidum  Lucus.  Where,  on  the  other  hand, 
the  long  chain  of  lighter  land,  called  by  Schiaparelli 
islands,  and  stretching  from  the  Solis  Lacus  region  west- 
ward to  Hellas,  offered  only  here  and  there  an  exit, 
the  canals  made  for  these  exits.  The  canals  in  the  Mare 


CHAP,  xix    CANALS   IN   THE   DARK  REGIONS  245 

Sirenum,  the  MareCimmerium,  and  the  Mare  Tyrrhenum 
struck  more  or  less  diagonally  across  those  seas  from 
their  northern  termini  to  the  entrances  of  the  straits 
between  the  islands,  thus  lacing  the  seas  in  the  way  a 
sail  is  rolled  to  its  spar.  From  the  exact  manner  in 
which  they  connected  with  the  light-region  canals  they 
proved  the  two  to  be  part  and  parcel  of  one  system, 
which  in  its  extension  was  planet-wide  and  therefore 
proportionately  important.  Whatever  of  strange  inter- 
est the  curious  characteristics  of  the  canals  themselves 
suggested  was  now  greatly  increased  by  this  addition ; 
for  the  solidarity  of  the  phenomenon  affected  the 
cogency  of  any  argument  derived  from  it. 

In  1894  only  the  dark  areas  of  the  southern  hemi- 
sphere were  found  to  be  thus  laced  with  lines.  For  then 
so  great  was  the  tilt  of  the  planet's  south  pole  toward 
the  earth,  that  while  those  zones  were  well  displayed 
the  dark  patches  of  the  northern  hemisphere  were  more 
or  less  hull-down  over  the  disk's  northern  horizon. 

Contrast  was  the  open  sesame  to  their  detection. 
When  the  maria  show  dark,  the  lines  are  lost  in  the 
sombreness  of  the  background.  As  the  maria  lighten 
the  lines  come  out'.  Such  was  amply  witnessed  by 
the  effect  in  1894  and  1896.  In  1894  I  found  it  impos- 
sible to  perceive  them,  except  where  the  Padargus 
crossed  Atlantis,  for  the  hue  of  the  maria  themselves 
was  then  very  dark.  In  1896,  on  the  other  hand,  I  saw 


246  MAES  AND  ITS  CANALS  CHAP,  xix 

them  without  difficulty.  What  is  also  of  interest :  so 
soon  as  seen  they  appeared  small,  without  haziness 
or  distention. 

As  the  oppositions  succeeded  one  another  the  north- 
ern regions  rose  into  view,  and  with  their  appearance 
came  the  detection  in  them  of  the  same  phenomena. 
No  large  dark  areas  like  the  diaphragm  exist  there,  but 
the  smaller  patches  of  blue-green  which  bestrew  them 
proved  to  be  similarly  meshed.  At  first  canals  were 
evident  upon  their  peripheries,  contouring  them  about ; 
then  the  bodies  themselves  of  the  patches  showed  grid- 
ironed  by  lines. 

The  Mare  Acidalium  with  its  adjuncts,  the  Lucus 
Niliacus  on  the  south  and  the  Lacus  Hyperboreus  on 
the  north,  thus  stood  out  in  1901.  On  a  particularly 
good  evening  of  definition  at  the  end  of  May,  the  Mare 
suddenly  made  background  for  a  sunburst  of  dark  rays, 
six  of  them  in  all  radiating  from  a  point  between  it  and 
the  Lacus  Hyperboreus.  Considering  how  sombre  the 
Mare  was  at  the  time,  this  was  as  remarkable  a  vision 
as  it  was  striking  to  see.  Although  at  the  moment 
the  sight  was  of  the  nature  of  a  revelation ;  these  lines 
have  been  amply  verified  since,  as  the  Martian  season 
has  proved  more  propitious. 

Similar  decipherment  has  befallen  all  the  other 
patches  of  blue-green  in  the  northern  hemisphere; 
these  having  shown  themselves  first  circumscribed  and 


CHAP,  xix    CANALS  IN   THE  DARK  REGIONS  247 

then  traversed  by  canals.  Interesting  instances  were 
the  Wedge  of  Casius  and  the  Propontis.  These  mark- 
ings, first  perceived  years  ago  as  mere  patches  of  shad- 
ing, then  partially  resolved  by  Schiaparelli,  now  stood 
revealed  as  a  perfect  network  of  lines  and  spots.  So 
many  of  both  kinds  of  their 
detail  occupied  the  ground 
that  to  identify  them  all  was 
matter  of  exceeding  difficulty. 
The  outcome  is  shown  in  the 
diagrammatic  representations 
opposite  and  on  page  256.  The  Pr°p°ntis'  190°- 
These  drawings  disclose  better  than  any  description 
the  mass  of  detail  of  which  the  patches  are  in  reality 
composed,  and  serve  to  convey  an  idea  of  the  com- 
plexity involved.  If  the  general  canal  system  seem 
intricate,  here  is  something  which  exceeds  that  as 
much  again. 

The  extension  in  this  manner  of  the  curious  trian- 
gulation  of  the  light  areas  into  and  through  all  the 
dark  areas  as  well,  by  thus  spreading  the  field  of  its 
operations  over  both  terranes  complexioned  so  unlike, 
greatly  increases  the  cogency  of  the  deduction  that  this 
detail  is  of  later  origin  than  the  background  upon  which 
it  rests.  That  the  mesh  of  lines  covers  not  only  the 
ochre  stretches  of  the  disk,  but  the  blue-green  parts  as 
well,  makes  it  still  more  certain  that  it  is  not  a  sim- 


248  MAES  AND  ITS   CANALS  CHAP,  xix 

pie  physical  outcome  of  the  fundamental  forces  that 
featured  the  planet's  fape.  For  in  that  case  it  could 
not  with  such  absolute  impartiality  involve  both  alike. 
Thus  here,  again,  we  find  corroboration  by  later  ob- 
servations of  what  earlier  ones  established. 

A  last  link  in  the  chain  of  canal  sequences  remains 
to  be  recorded.  Just  as  the  lines  in  the  dark  regions 
continued  those  in  the  light,  so  they  themselves  turned 
out  to  be  similarly  prolonged  and  in  no  less  suggestive 
a  manner.  For  when  the  north  polar  zone  came  to  be 
displayed,  canals  were  evident  there,  continuing  those 
in  the  other  zones  and  running  at  their  northern  ends 
into  dark  spots  at  the  edge  of  the  polar  cap.  Here, 
then,  we  have  the  end  of  the  whole  system,  or  more 
properly  its  origin,  in  the  polar  snows.  The  signifi- 
cance of  this  will  be  seen  from  other  phenomena,  to  a 
consideration  of  which  we  now  proceed. 


CHAPTER   XX 

OASES 

"VTEXT  to  be  caught  of  the  details  of  this  most  curi- 
ous network  that  meshes  the  surface  of  Mars  was 
a  set  of  phenomena  stranger  even  than  the  lines ;  to  wit, 
dark  round  dots  standing  at  their  intersections.  More 
difficult  to  make  out  than  the  lines,  they  were  in  conse- 
quence detected  thus  later  by  fifteen  years.  Once 
discovered,  however,  it  became  possible  to  trace  their 
unconscious  recognition  back  in  time.  Thus  Schiapa- 
relli  told  the  writer  in  1895,  apropos  of  those  found  at 
Flagstaff,  that  he  had  himself  suspected  them  but  could 
not  make  sure.  Some  of  them  stand  figured  in  his 
Memoria  Sesta  dealing  with  the  opposition  of  1888,  but 
not.  published  till  1899.  In  such  posthumous  recogni- 
tion, as  one  may  call  it,  the  spots  repeated  the  history 
of  the  canals.  For  Schiaparelli  had  himself  pointed 
out  a  similar  preconscious  visioning  of  the  canals  in 
the  delicate  pencilings  of  Dawes  and  the  streaks  of 
Lockyer,  Kaiser,  and  Secchi,  now  translatable  as  rep- 
resenting the  Phison,  the  Euphrates,  and  half  a  dozen 
other  canals  imperfectly  seen.  That  both  the  canals 
and  the  oases  were  thus  sketched  before  they  were  seen 

249 


250  MAES  AND  ITS   CANALS  CHAP,  xx 

well  enough  to  be  definitely  discovered  is  to  an  un- 
prejudiced mind  among  their  strongest  credentials  to 
credit. 

Nor  was  Schiaparelli  the  sole  person  thus  to  get  proof 
before  letter.  One  of  their  very  earliest  portrayals 
appears  in  a  drawing  by  Otto  Boeddicker,  made  on 
December  26,  1881,  where  the  Pseboas  Lucus  is  clearly 
represented.  In  a  still  more  imperfect  manner  some 
of  the  spots  had  been  adumbrated  and  their  shadows 
drawn  long  before  that.  Thus  they  may  be  deciphered 
as  the  cause  of  patches  drawn  by  Dawes  in  1864, 
though  none  of  them  were  in  any  definite  sense  de- 
tected till  1879,  and  only  then  so  ill  defined  that  their 
true  character  was  not  apparent.  As  patches  they  are 
still  commonly  seen  at  observatories  where  the  obser- 
vational conditions  are  not  of  the  best  and  the  study 
of  the  planet  not  systematically  enough  pursued  to  have 
them  disclose  their  true  shape  and  size. 

The  history  of  their  detection  is  resumed  in  the 
experience  of  the  individual  observer.  During  the 
course  of  my  own  observations  I  have  had  occasion  to 
notice  the  several  stages  in  recognition  of  the  spots 
which  have  marked  their  chronologic  career.  As  with 
the  lines,  three  stages  in  the  appearance  of  the  spots 
may  be  remarked:  first,  where  the  scattering  of  the 
rays  is  so  wide  that  dilution  prevents  anything  from 
being  seen;  second,  where  the  commotion  being  less 


CHAP,  xx  OASES  251 

the  object  appears  as  a  gray  patch;  and  third,  where 
in  comparative  quiet  it  condenses  into  a  black  dot. 
For  the  two  former  our  own  air  waves  are  to  blame. 
In  coursing  waves  of  condensation  and  rarefaction  they 
spread  the  image  of  the  spot  as  they  do  that  of  the 
canal.  Then  as  the  currents  calm  the  spot  shrinks 
to  its  normal  proportions,  and  in  so  doing  darkens  in 
consequence  of  being  less  widely  diffused.  Thus  the 
evolution  in  perception  which  may  take  place  in  the 
course  of  an  hour  for  a  particular  observer  represents 
exactly  what  has  occurred  in  the  person  of  the  race  by 
the  improvement  in  observational  methods  and  sites. 

That  the  spots,  although  wider  than  the  canals,  re- 
mained longer  hidden  from  human  sight,  is  due  to  the 
optico-physic  fact  that  a  tenuous  line  may  be  perceived 
owing  to  its  length  when  a  dot  of  the  same  diameter 
would  be  invisible.  Summation  of  impressions  is  un- 
doubtedly the  cause  of  this.  The  mere  fact  that  a  row 
of  retinal  cones  is  struck,  although  each  be  but  feebly 
affected,  is  sufficient  to  raise  the  sum  total  into  the 
sphere  of  consciousness. 

In  the  second  stage  of  their  visibility,  the  spots  are  in 
danger  of  mistake  with  the  smaller  true  patches  of  som- 
bre hue  which  fleck  the  northern  hemisphere  of  the 
planet  and  from  which  they  differ  totally  in  kind,  totally 
so  far  as  our  present  perception  goes.  Such  true 
patches  consist  of  a  groundwork  of  shading,  upon  which, 


252  MARS  AND    ITS  CANALS  CHAP,  xx 

indeed,  are  superposed  the  usual  network  of  lines  and 
spots.  Prominent  as  instances  of  them  are  the  Trivium 
Charontis,  the  Wedge  of  Casius,  and  the  Mare  Acidalium. 
With  patches  of  the  sort  the  spots  proper  must  not  be 
confounded. 

Close  treading  on  the  heels  of  the  detection  of  lines 
athwart  the  seas  came  the  recognition  of  spots  there 
likewise.  At  the  opposition  of  1896-1897  the  num- 
ber was  added  to;  and  so  the  tale  has  been  steadily 
increased.  Their  number  as  found  at  Flagstaff  up  to 
the  present  time,  that  is,  to  the  close  of  the  opposition 
of  1905,  is  186;  of  which  121  lie  in  the  light  regions, 
42  in  the  dark  areas  of  the  southern  hemisphere,  and 
23  in  the  smaller  sombre  patches  of  the  northern  zones. 

From  their  relationships  and  behavior  it  became 
apparent  that  the  spots  were  not  lakes  but  something 
which  answered  much  more  nearly  to  oases. 

Of  the  spots  three  kinds  may  be  distinguished :  the 
large,  the  little,  and  the  less,  if  by  the  latter  term  it  may 
be  permitted  to  denote  what  has  but  collateral  claim 
to  be  included  and  yet  demands  a  certain  recognition. 
For  though  not  spots  like  the  others,  the  members  of 
the  third  class  have  certain  traits  in  common  with  them 
while  differing  radically  in  others. 

To  the  kind  called  large  belong  the  greater  number 
of  spots  so  far  found  upon  the  disk.  They  are  large 
only  by  comparison  with  the  little.  For  they  measure 


CHAP,  xx  OASES  253 

according  to  my  latest  determinations  but  seventy- 
five  or  one  hundred  miles  in  diameter ;  on  the  planet 
some  two  degrees  across.  Sizable  black  pin-heads, 
it  is  their  tone  that  chiefly  catches  the  eye,  for  they 
•are  commonly  the  darkest  markings  on  the  disk. 
Against  the  ochre  stretches  they  appear  black,  and 
even  in  the  midst  of  the  dark  areas  they  stand  out 
almost  as  much  contrasted  with  their  surroundings 
as  these  do  with  the  light  regions  themselves.  About 
a  hundred  and  forty  are  now  known.  Those  in  the 
light  areas  were  discovered  first;  those  hi  the  dark 
regions  being  harder  to  see. 

Of  this  first  kind  are  such  spots  as  the  Pseboas  Lucus, 
the  Aquae  Calidae,the  Lacus  Phoenicis,  and  the  Novem 
Viae;  or,  in  English,  the  Grove  of  Pseboas,  the  Hot 
Springs,  the  Phoenix  Lake,  and  the  Nine  Ways,  to  men- 
tion no  more.  That  they  bear  dissimilar  names  implies 
no  dissimilarity  in  structure.  The  phenomena  are  all 
remarkably  alike,  and  clearly  betoken  one  and  the 
same  class  of  objects;  differing  between  themselves 
at  most  in  size  and  importance. 

In  form  they  all  seem  to  be  round.  They  certainly 
appear  so,  and  were  it  not  that  retinal  images  of  small 
areas  tend  to  assume  this  shape  might  implicitly  be 
credited  with  being  what  they  seem.  The  reason  for 
optical  circularity  probably  resides  in  the  shape  of  the 
retinal  cones  and  in  their  patterning  into  a  mosaic 


254 


MARS   AND  ITS   CANALS 


floor.  So  that  unless  a  sufficient  number  of  cones  be 
struck  the  image  takes  on  to  consciousness  a  roughly 
circular  figure  —  whether  it  be  so  in  fact  or  not.  In 
the  present  case,  however,  they  seem  to  be  too  well 
seen  for  self-deception  of  the  sort. 

The  little  are  distinguished  from  the  large  by  being 
pin-points  instead  of  pin-heads.  They  are  most  mi- 
nute; from  fifteen  to  twenty-five  miles  in  diameter 
only.  That  anything  except  size  distinguishes  the 
two  apart  is  from  their  look  improbable.  In  color  or 
rather  tone,  —  for  distinctive  color  is  of  such  minute 
objects  unpredicable,  —  they 
would  seem  to  be  alike. 
Such  is  also  the  case  with 
their  distribution  and  detail 
association. 

To  the  second  class  be- 
long the  Fons  Juventae,  — 
Schiaparelli's  Fountain  of 
Youth,  —  the  Fons  Immor- 
talis  in  Elysium  in  1905,  and  the  Gygaea  Palus,  besides 
many  more.  These  are  all  pin-points,  just  upon  the 
limit  of  vision,  and  noteworthy  chiefly  for  being  visible 
at  all.  All  those  detected  so  far  lie  not  very  distant 
from  the  equator,  which  may  or  may  not  be  a  matter  of 
accident.  It  is  not  one  of  perception,  since  this  part 
of  the  planet  was  not  the  best  place  for  observation  at 


Fons  Immortalis,  June  19. 


CHAP,  xx  OASES  255 

the  time  they  were  discovered.  To  make  out  one  of 
these  little  dots  is  a  peculiarly  pleasing  bit  of  observa- 
tion, as  it  requires  particularly  good  definition.  One 
might  almost  take  them  for  fly-specks  upon  the  image 
did  they  not  move  with  the  disk.  They  have  no  per- 
ceptible size  and  yet  are  clearly  larger  in  diameter  than 
the  canals  which  run  into  them;  which  proves  how 
very  slender  the  latter  must  be. 

Very  early  in  the  detection  of  the  spots  it  became 
evident  that  they  were  not  scattered  haphazard  over 
the  surface,  but  that  on  the  contrary  they  were  never 
found  except  at  the  meeting-points  of  the  lines.  From 
this  it  must  not  be  supposed,  as  has  been  done,  that  the 
spots  are  merely  optical  reinforcements  of  the  lines  at 
their  crossings  due  to  the  more  crowded  character 
there  of  the  lines  themselves.  That  they  are  not  such 
is  demonstrated  by  the  existence  of  crossings  where, 
either  temporarily  or  permanently,  none  appear; 
which  shows  that  they  are  far  too  well  seen  for  any 
such  illusion  about  them  to  be  possible.  At  these  cross- 
ings the  lines  traverse  one  another  without  thickening, 
whether  they  be  single  or  double  lines.  The  spots, 
on  the  other  hand,  are  much  wider  than  the  lines, 
giving  a  beaded  look  to  the  threads.  In  short,  they 
are  the  knots  to  the  canal  network.  All  the  more  im- 
portant junctions  are  characterized  by  their  presence. 
Such  starred  junctions  are  not  confined  to  the  ochre 


256  MAES   AND   ITS   CANALS  CHAP,  xx 

regions;  they  dot  the  light  and  the  dark  areas  with 
equal  impartiality,  thus  showing  themselves  to  be  in- 
dependent of  the  nature  of  the  ground  where  large 
stretches  of  country  are  concerned.  On  the  other  hand, 
they  appear  to  be  unusually  numerous  in  the  smaller, 
isolated,  dark  areas  of  the  northern  hemisphere,  such 


as  the  Trivium,  the  Mare  Acidalium,  the  Propontis, 
and  the  Wedge  of  Casius.  Here  they  crowd ;  and  one 
cannot  avoid  the  inference  that  their  plentifulness  in 
these  regions  is  not  due  to  chance. 

To  the  large  spots,  those  of  the  first  class,  fall  the 
places  of  intersection  of  the  largest  and  most  numer- 
ous canals,  while  the  little  spots  make  termini  to 
fainter  lines,  ones  that  bear  to  them  a  like  ratio  of  un- 
importance. Spots  and  lines  are  thus  connected  not 
simply  in  position  but  in  size.  The  one  is  clearly 
dependent  on  the  other,  the  importance  of  the  centre 
being  gauged  by  the  magnitude  of  its  communications. 


CHAP,  xx  OASES  257 

From  the  fact  of  association  we  now  pass  to  the  man- 
ner of  it,  which  is  quite  as  remarkable.  The  position 
of  the  spot  relative  to  its  tributary  canals  depends  upon 
the  character  of  the  connecting  lines.  If  the  canal  be 
single  it  runs,  so  far  as  may  be  judged,  straight  into 
the  middle  of  the  oasis,  or,  in  other  words,  the  oasis 
is  symmetrically  disposed  about  its  end.  This  is  true 
of  the  greater  number  of  the  large  spots  and  of  all  the 
little  ones,  since  the  latter  have  as  connections  only 
single  canals. 

In  the  case  of  a  double  canal  arriving  at  a  spot,  a  differ- 
ent and  most  curious  dependence  is  observable.  This 
fact  I  first  noticed  in  a  general  way  at  the  opposition  of 
1896-1897,  the  initial  appearance  of  it  being  presented 
on  September  30,  1896,  by  the  Coloe  Palus  and  the 
Phison.  It  was  again  visible  in  the  case  of  the  spots 
in  the  Trivium  at  the  tune  the  canals  leading  to  that 
place  doubled  in  March,  1897.  But  the  exact  nature 
of  the  phenomenon  was  not  fully  appreciated  till 
1903,  when  the  thing  was  seen  so  well  as  to  appear 
cut  on  copper  plate.  It  was  this :  the  spot  is  exactly 
embraced  between  the  two  arms  of  the  double  canal. 
It  is,  moreover,  seemingly  perfectly  round  and  just 
fits  in  between  the  parallel  lines.  The  Ascraeus  Lucus 
was  the  first  spot  that  showed  thus  in  association  with 
the  double  Gigas.  Others  followed  suit  in  so  showing, 
several  specimens  presenting  themselves  so  well  as  to 


258  MARS  AND  ITS  CANALS  CHAP,  xx 

leave  no  doubt  of  the  precise  connection.  The  sight 
presented  by  such  a  spot  and  its  incasing  double  is  a 
beautiful  bit  of  detail,  perhaps  the  most  beautiful  so 
far  to  be  seen  upon  the  Martian  disk.  The  distinct- 
ness with  which  it  stands  out  on  occasion  suggests 

a  steel  engraving, 
and  shows  how 
clear-cut  the  Mar- 
tian  features  really 
are  when  our  own 
air  ceases  from 
/f*j.  troubling  and  al- 
lows them  to  be 
at  rest.  Incidentally,  we  may  note  that  this  phe- 
nomenon alone  serves  to  disprove  the  diplopic  theory 
of  the  production  of  the  double  canals.  For  if  a  double 
were  a  single  line  seen  out  of  focus,  any  spot  upon  it 
should  be  doubled  too. 

It  may  seem  to  the  reader  as  if  what  was  seen 
in  1903  was  but  an  unimportant  advance  over  the 
observed  phenomena  of  1896-1897.  Not  so,  however. 
For  with  the  earlier  instances  it  was  not  possible 
to  be  sure  of  the  precise  limits  of  the  spot  with  regard 
to  the  double.  The  Coloe  Palus,  on  the  one  hand,  did 
not  fill  all  the  space  apparently  between  the  double 
Phison;  while  the  Lucus  Ismenius  more  than  did  so 
with  the  double  Euphrates.  To  have  set  down  the 


CHAP,  xx  OASES  259 

different  appearances  to  insufficient  definition  would 
have  been  a  great  mistake,  as  subsequent  observation 
has  served  to  show.  The  Lucus  Ismenius  instances 
this.  In  1896-1897  it  was  seen  terminating  the  Eu- 
phrates, blocking  all  the  space  between  the  two  lines 
and  extending  a  little  upon  either  side  of  them.  Now, 
from  its  appearance  in  1901  it  was  evident  that  the 
effect  had  been  produced  by  twin  spots  lying  along 
the  Deuteronilus,  the  axis  joining  them  being  perpen- 
dicular to  the  Euphrates.  In  1903  the  relation  was 
still  better  explained  by  what  appeared  then,  when  not 
only  did  the  two  spots  stand  out,  but  the  Euphrates 
showed  with  a  line  running  centrally  into  each. 

Although  originally  seen  by  Schiaparelli  as  a  single 
spot  and  so  at  first  seen  by  me,  better  acquaintance 
with  the  disk  disclosed  to  both  observers  its  really  dual 
character.  As  this  pair  has  persisted  through  all  three 
of  the  most  recent  oppositions,  it  seems  fairly  certain 
that  it  is  always  of  this  character,  and  more  fitting, 
therefore,  to  give  it  the  plural  appellative.  This 
is  the  single  instance  of  a  double  oasis.  There  are 
many  that  lie  close  together  and  might  be  taken  as 
such ;  but  this  is  the  only  one  where  the  connection  is 
intrinsic.  According  to  measures  of  the  drawings  of 
1905  extending  through  six  presentations,  the  distance 
between  the  twin  oases  is  4°.2. 

Their  relation  to  the  canals  which  run  into  them  is  of 


260 


MARS   AND   ITS  CANALS 


the  most  complicated  description  and  of  the  most  sug- 
gestive character.  For  to  the  twin  spots  converge 
no  less  than  seven  double  canals,  one  wedge-shaped 
pair  and  three  single  canals,  a  most  goodly  number  of 
communication  lines.  Four  of  the  double  canals  run 
into  the  oases  with  one  line  to  each ;  these  canals  are 
the  Astaboras,  the  Naarmalcha,  the  Euphrates,  and  the 
Hiddekel.  Three  doubles,  the  Protonilus,  the  Djihoun, 
and  the  Deuteronilus,  embrace  the  oases  between  their 
two.  lines,  while,  in  the  singles,  the  canal  connects  with 
one  or  other  of  the  twins,  as  the  case  may  be. 

Now,  there  is  method  as  to  which  of  the  doubles 
shall  straddle,  which  embrace,  the  two  Ismenii.  Those 
which  leave  the  place  parallel 
or  nearly  so  to  the  direction 
joining  the  Luci,  inclose 
them  both;  those  of  which 
the  setting  forth  is  at  an 
angle  to  this  direction  depart, 
each  line  of  the  pair,  from 
the  eastern  and  the  western 

Peculiar  association  of  the  Luci     gpot  respectively. 
Ismenii  with  double  canals. 

Consider,  now,  the  dispo- 
sition of  these  seven  pairs  of  lines.  All  of  them  lie  in 
one  semicircle  about  the  Luci,  beginning  with  the 
Protonilus  on  the  east  and  ending  with  the  Deuter- 
onilus on  the  west.  Furthermore,  all  follow  approxi- 


CHAP,  xx  OASES  261 

mately  arcs  of  great  circles,  except  the  Djihoun,  and 
all  send  one  of  their  twin  lines  to  one  Lucus,  one  to 
the  other.  The  data  are  enough  to  make  this  state- 
ment possible.  Although  the  west  line  of  the  Naar- 
malcha  has  not  been  caught  entering  its  oasis,  the  east 
one  has  been  seen  to  enter  the  other,  and  the  width  of 
the  double  shows  that  the  west  one  must  enter  the 
corresponding  spot.  In  the  case  of  the  Astaboras  the 
double  has  only  been  observed  as  far  as  the  Vexil- 
lum,  but  the  south  line  has  continued  on  to  the  west 
Ismenius,  and  here  again  the  width  makes  it  certain 
that  were  the  canal  double  throughout,  the  other  line 
must  enter  the  east  Ismenius.  From  the  base  line  of 
the  Proto-Deuteronilus  the  inclinations  of  the  seven 
pairs  are  as  follows :  — 

Protonilus          ....        0°  Due  East 
Astaboras          .        .        .        .      40°  North  of  East 
Naarmalcha      .        .        .        .70°  North  of  East 
Euphrates          .        .        .        .80°  North  of  West 

Hiddekel 55°  North  of  West 

Djihoun 0°  North  of  West 

Deuteronilus      ....        0°  Due  West 

Now,  the  width  between  the  two  lines  of  the  four  canals 
to  the  east  increases  regularly  from  the  Protonilus 
round ;  the  Protonilus  being  the  narrowest  double,  the 
Astaboras  the  next>  the  Naarmalcha  the  next,  and  the 
Euphrates  the  widest.  And  from  the  width  between 
the  twin  oases,  it  would  seem  that  they  severally  enter 


262  MARS  AND  ITS  CANALS  CHAP.  xx 

the  centres  of  them.  What  takes  place  in  the  case  of 
the  Hiddekel,  which  is  wider  than  its  tilt  would  imply, 

and   in    the    Dji- 

houn,     which     is 

\V/  narrower,    is    not 

^2>Pp  so     clear.       But 

that    they    enter 
JMM  lf*»<*,lKj.      'J#*H£./j*3±     the  oases  in  some 

place  is  certain. 

The  spots  make 

common  termini  for  all  the  canals  of  a  given  neigh- 
borhood. In  other  words,  canals  converge  to  the 
places  occupied  by  the  spots  and  do  not  cross  hap- 
hazard according  to  the  laws  of  chance.  Only  one 
instance  exists  where  a  spot  fails  to  gather  to  itself 
the  whole  sheaf  of  canals  and  even  there  it  collects 
all  but  two.  This  anomaly  is  the  Pseboas  Lucus. 
The  peculiarity  of  this  oasis  is  that  it  lies  not  on, 
but  just  off,  the  Protonilus.  That  it  does  so  is  ex- 
ceeding curious,  considering  that  it  is  the  sole  example 
of  such  extra-canaline  position.  Strictly  speaking,  it  is 
not  the  Protonilus  but  the  point  where  the  Protonilus 
turns  into  the  Nilosyrtis  to  which  it  stands  thus  neigh- 
boringly  aloof.  And  this  may  explain  the  anomaly. 
For  the  Nilosyrtis  has  not  the  full  geometric  regu- 
larity of  the  normal  canal,  and  seems  to  have  been 
a  more  or  less  fundamental  feature  of  the  region. 


CHAP,  xx  OASES  263 

For  the  rest,  the  Lucus  has  the  form  and  possesses 
the  canal  connections  appropriate  to  its  state.  It  is 
apparently  round,  and  lies  between  the  twin  lines  of  the 
Phison  and  also  between  those  of  the  Vexillum. 

Not  far  from  the  Pseboas  Lucus  are  to  be  found  all 
the  examples  of  the  third  class  of  spots ;  for  so  far  they 
have  not  been  observed  outside  of  Aeria,  a  region  pe- 
culiarly peopled  -by  double  canals.  With  double  canals 
they  are  necessarily  associated,  inasmuch  as  they  con- 
sist of  shading  in  the  form  of  a  square  or  parallelogram, 
filling  the  deltas  between  two  pairs  that  cross.  Thus 
have  shown  the  Coloe  Palus  at  the  crossing  of  the  double 
Phison  with  the  double  Astaboras,  and  the  Juturna 
Fons  where  the  double  Sitacus  traverses  the  double 
Euphrates. 

At  these  same  places  a  fourth  kind  is  sometimes  no- 
ticeable :  a  four-square  set  of  pin-points  or  a  two-square 
set  of  the  same  at  the  corners  of  the  line -made  parallelo- 
gram. This  kind  may  well  be  synchronous  with  the 
third,  though  it  has  only  been  noticed  at  consecutive 
presentations.  The  third,  however,  has  no  observed 
dependence  upon  the  first  or  second  classes.  And  this 
serves  to  make  more  probable  the  true  objectivity 
of  the  circular  and  the  square  figures  respectively 
shown  by  each. 

The  spots  apparent  in  the  dark  regions  do  not  appre- 
ciably differ  in  either  size  or  shape  from  the  bulk  of 


264  MARS   AND  ITS   CANALS  CHAP,  xx 

those  visible  in  the  light.  Equally  with  them  they 
seem  to  be  round,  small,  and  nearly  black.  They 
would  seem,  too,  in  the  great  diaphragm  —  or  larger 
contiguous  sombre  region  —  to  be  equally  plentifully 
distributed. 


CHAPTER  XXI 

CARETS  ON  THE   BORDERS  OF  THE   GREAT  DIAPHRAGM 

T^UNCTIONALLY  related  to  the  canal  system, 
-*-  and  yet  in  look  and  location  contrasted  with  its 
other  details,  is  a  further  set  of  markings,  detected  by 
me  in  1894,  and  reseen  at  subsequent  oppositions 
since,  along  the  north  border  of  the  southern  seas. 
They  lie  upon  what  used  to  be  thought  the  con- 
tinental coastline,  the  fringing  edge  of  that  almost 
continuous  band  of  shading  that  belts  the  Martian 
globe  throughout  the  southern  subtropic  zone  •  and 
called  by  Schiaparelli  the  great  diaphragm.  The  ter- 
rane  lends  itself  to  the  appellative,  forming,  as  it  does, 
a  dark  dividing  strip  of  country  between  the  brilliant 
reddish-ochre  hemisphere  on  the  north  and  the  half- 
toned  islands  to  the  south  of  it.  By  Schiaparelli  it 
was  thought  to  be  one  long  Mediterranean,  and  though 
its  marine  character  is  now  disproved,  that  it  lies 
lower  than  the  bright  ochre  regions  is  likely.  To  this 
difference  of  level  is  probably  due  the  peculiar  phe- 
nomenon which  there  manifested  itself  to  careful  scru- 
tiny in  1894.  For  it  was  there  only  that  it  occurred. 
The  phenomenon  in  question  consisted  of  nicks  in 

265 


266  MAES  AND  ITS  CANALS  CHAP,  xxr 

the  coastline,  of  triangular  shape  and  filled  with  shad- 
ing. They  occurred  at  intervals  along  it  and  were  of 
the  general  form  of  carets,  such  marks  as  one  makes 
in  checking  items  down  a  list.  Their  position  was  al- 
ways where  a  canal  debouched  from  the  diaphragm 
upon  its  career  across  the  open  continent.  The  canal 
itself  was  by  no  means  necessarily  visible.  On  the 
contrary,  at  first  it  was  usually  absent.  Such  was  the 
case  with  those  marking  the  departure-points  of  the 
Phison  and  Euphrates  and  of  the  Amenthes  and 
Lethes,  which  appeared,  without  being  well  defined, 
from  the  moment  the  planet  came  to  be  scanned. 

One  by  one  these  carets  stood  out  to  view,  punctuating 
the  points  where  canals  later  were  to  show  or  termi- 
nating those  that  already  existed.  Strung  thus  with 
them  at  intervals  was  the  whole  coastline  of  the  dia- 
phragm, beginning  with  the  Mare  Icarium  and  stretch- 
ing round  through  the  Mare  Tyrrhenum,  Mare  Cim- 
merium,  Mare  Sirenum,  and  Mare  Erythraeum  to  the 
Mare  Icarium  again.  As  the  planet  got  nearer  to  the 
earth  their  peculiar  shape  began  to  define  itself,  and  it 
was  again  in  the  case  of  those  giving  origin  to  the  Phison 
and  Euphrates  that  the  recognition  came  first.  What 
had  appeared  earlier  simply  as  a  spot  now  stood  out 
as  two  triangular  notches,  indenting  the  coast  and  giving 
exit  at  their  apices,  the  eastern  one  to  the  Phison,  the 
western  to  the  Euphrates.  These  were  the  things, 


CHAP,  xxi       CARETS   ON  THE  DIAPHRAGM  267 

then,  that  had  constituted  the  Portus  Sigaeus  of  Schia- 
parelli. 

Commonly  the  carets  lie  at  the  bottom  of  well-marked 
bays,  as,  for  example,  those  terminating  the  Syrtis 
Minor  and  the  Sinus  Titanum.  But  frequently  they 
are  placed  in  the  very  midst  of  a  long  and  otherwise 
unaccented  coast,  as  is  the  case  in  mid-course  of  the 
Mare  Cimmerium  and  the  Mare  Sirenum.  Yet  in  no 
instance  is  the  thing  unassociated  with  a  canal.  In 
every  case  one  or  more  canals  leave  the  caret  for  their 
long  traverse  down  the  disk. 

This  is  not  their  only  canal  connection.  When  the 
canals  in  the  dark  regions  came  to  be  discovered,  each 
of  them  was  found  by  me,  as  nearly  as  difficult  obser- 
vations would  permit,  to  be  associated  with  the  caret 
upon  its  other  side.  Thus  the  lacing  of  the  Mare  Cim- 
merium and  Sirenum  used  them  as  its  reeving-points. 
Similarly  those  at  the  mouths  of  the  Phison  and  Eu- 
phrates did  duty  likewise  to  the  Maesolus  and  the  Ion. 
In  such  manner  the  carets  stood  in  dual  relation  to 
canals ;  subserving  a  purpose  to  the  light-region  canals 
on  the  one  hand  and  to  the  dark-region  ones  on  the 
other.  In  a  way  the  caret,  then,  holds  the  same  position 
toward  the  canals  that  do  the  spots  in  the  light  or  dark 
regions.  Like  them  it  is  a  canal-distribution  point. 
Unlike  them,  however,  in  shape  it  is  triangular  instead 
of  round,  and  we  are  piqued  to  inquire  to  what  cause 


268  MARS   AND  ITS   CANALS  CHAP,  xxi 

it  can  owe  its  different  contour.  The  answer  seems  to 
lie  in  the  character  of  the  locality,  not  simply  in  its 
complexion.  For  the  spots  in  both  the  northern  and 
the  southern  dark  patches  are  as  circular  as  those  stand- 
ing in  the  light,  whether  they  lie  in  the  centre  or  upon 
the  edges  of  them.  The  edges  of  the  northern  patches, 
however,  and  the  other  sides  of  the  southern  ones  do 
not  present  the  clear-cut  character  of  the  northern  coast 
of  the  diaphragm.  Where  they  seem  to  be  definitely 
bounded  they  are  so  by  darker  canals.  This  hints 
that  their  contours  are  not  defined  by  antithesis  of 
level,  while  that  of  the  northern  coast  of  the  great  dia- 
phragm is.  Difference  of  altitude  is  then  concerned  in 
their  constitution;  the  canal  system  here  falls  to  a 
lower  level,  and  these  triangular  spots  instead  of  round 
ones  are  the  result.  Topographic  only,  such  explana- 
tion leads  the  way  to  a  more  teleologic  one,  and  serves 
even  on  first  acquaintance  to  stir  curiosity  to  some 
satisfying  cause. 

Suggestive  in  several  ways  for  its  resemblance  to  the 
carets  is  another  detail  not  far  distant  from  the  Portus 
Sigaei,  the  twin-forked  Sabaeus  Sinus.  Curiously 
enough,  this  feature  of  Mars,  which  has  been  well 
known  and  recognized  ever  since  the  eagle-eyed  Dawes 
detected  it  more  than  forty  years  ago,  proves  to  be  a 
sort  of  connecting  link  between  the  main  markings  and 
the  details  of  more  modern  detection.  The  twin- 


CHAP,  xxi       CARETS   ON   THE  DIAPHRAGM  269 

forked  Sabaeus  Sinus,  as  its  name  implies,  is  of  the 
form  of  a  double  bay ;  was  considered  to  be  one  in  fact 
so  long  as  the  maria  were  held  to  be  seas.  It  straddles 
the  point  of  land  which,  called  the  Fastigium  Aryn, 
has  been  taken  for  the  Greenwich  of  Martian  longitudes. 
Each  '  bay '  —  not  in  truth  a  bay  at  all  —  indents 
the  ochre  in  an  acute  triangle,  from  the  tip  of  which 
many  canals  proceed  like  the  rays  of  a  fan  from  a  hold- 
ing hand..  Both  tips  are  darker  than  the  main  body 
of  the  dark  mare  from  which  they  proceed.  They  thus 
recall  in  general  character  the  carets.  They  further 
reproduce  specifically  the  Portus  Sigaei,  for  they  give 
origin  to  two  doubles,  the  Gihon  and  the  Hiddekel, 
in  exactly  the  same  manner  that  the  two  nicks  of  the 
Portus  Sigaei  do  to  the  Phison  and  Euphrates.  Nor 
are  their  tips  much  farther  apart  than  those  of  the 
Portus,  five  degrees  measuring  the  spread  of  the  one 
and  four  degrees  that  of  the  other  respectively;  the 
reason  for  their  earlier  discovery  lying  in  their  greater 
size.  They  thus  perform  the  same  office  as  the  Portus 
Sigaeus,  are  quite  comparable  to  it  in  width,  and  differ 
in  shape  only  as  a  larger  and  more  acute  triangle  differs 
from  a  smaller  and  blunter  one.  Undreamt  of  by 
Dawes  and  unheeded  since,  they  were  the  first  hint  to 
the  world  of  the  duality  which  forms  so  strangely  per- 
vasive a  feature  of  the  canal  system  of  the  planet. 
Thus  the  carets  stand  connected  with  the  canals 


270  MAES  AND  ITS  CANALS  CHAP,  xxi 

quite  as  intimately  as  the  oases  but  in  a  significantly 
different  manner.  For,  in  addition  to  their  intermedi- 
ary standing  between  the  light  regions  and  the  dark, 
their  relation  to  the  doubles  is  peculiar.  An  instance  is 
offered  by  the  double  Euphrates  and  another  by  the 
Ganges.  The  Euphrates,  as  we  saw  in  Chapter  XVIII, 
leaves  the  Portus  Sigaei  at  the  south,  one  line  leaving 
each  caret  centrally,  so  that  each  caret  is  concerned  only 
with  its  own  line  and  has  no  connection  with  its  fellow. 
At  their  northern  ends  both  lines  have  similarly  each 
its  own  Lucus  Ismenius.  The  like  seems  to  be  true  of 
the  Ganges.  Similarly  the  twin  Titan,  have  each  its 
own.  Such  twin  duty  in  the  matter  of  doubles  seems 
to  be  the  rule  with  the  carets,  even  more  so  than  with 
the  oases ;  and  this  is  probably  from  the  fact  that  the 
coastline  is  of  more  limited  extent  than  the  interior. 

Altogether  the  carets  offer  to  our  inspection  glosses 
in  finer  print  upon  the  general  text  of  the  canals. 
Thought  upon  what  they  show  takes  us  a  step  farther 
toward  the  solution  of  the  strange  riddle  of  this  other 
world,  a  riddle  which  he  who  runs  may  not  read,  still 
less  scout,  and  which  only  reasoning,  without  prejudice 
or  partiality,  can  unravel. 


CHAPTER  XXII 

THE    CANALS   PHOTOGRAPHED 

"PHOTOGRAPHY  holds  to-day  a  place  of  publicity 
in  the  exposition  of  the  stars.  Directed  by  Draper 
to  the  heavens  thirty-four  years  ago,  the  camera  re- 
corded then  the  first  picture  ever  taken  of  the  moon. 
From  this  initial  peering  into  celestial  matters,  practice 
has  progressed  until  now  the  dry  plate  constitutes  one 
of  the  most  formidable  engines  in  astronomic  research. 
Not  most  effectively,  however,  in  the  field  which  might 
have  been  predicted.  Beautiful  as  the  lunar  present- 
ment was,  as  a  presentiment  of  what  was  coming,  it 
pointed  astray.  For  it  is  not  in  lunar  portrayal,  su- 
perbly as  its  crater  walls  in  crescent  chiaroscuro  or  its 
crags  that  cast  their  tapering  shadows  athwart  the  dial 
of  its  plains  stand  out  in  the  latest  photographs  of  our 
satellite,  that  the  camera's  greatest  service  has  since 
been  done.  Impressive  as  they  are,  these  pictorial 
triumphs  are  chiefly  popular,  and  appeal  on  their  face 
to  layman  and  scientist  alike.  Not  in  the  nearest  to 
us  of  the  orbs  of  heaven,  but  in  the  most  remote  has 
celestial  photography's  most  prolific  field  been  found 
to  lie.  Its  province  has  proved  preeminently  the  stars, 

271 


272  MARS   AND   ITS   CANALS  CHAP,  xxn 

especially  the  farthest  off,  and  that  star-dust,  the 
nebulae,  from  out  of  which  the  stars  are  made.  Reason 
for  this  explains  at  once  its  efficiency  and  its  limitations. 

Its  rival,  of  course,  is  the  eye.  It  is  as  regards  the 
eye  that  its  comparative  merits  or  demerits  stand  to 
be  judged.  Now,  thus  viewed,  its  superiority  in  one 
respect  is  unquestionable;  it  simply  states  facts. 
But  though  it  cannot  misinform,  it  can  color  its  facts 
by  giving  undue  prominence  to  the  effect  of  some  rays 
and  suppressing  the  evidence  of  others,  so  that  its 
testimony  is  not,  it  must  be  remembered,  always  in 
accord  with  that  of  human  vision.  Speaking  broadly, 
however,  it  is  so  little  complicated  a  machine  as  to 
register  its  results  with  more  precision  than  the  retina. 
The  evidence  of  the  camera  has  thus  one  important 
advantage  over  other  astronomic  documents :  it  is  im- 
personally trustworthy  in  what  it  states.  Bias  it  has 
none,  and  its  mistakes  are  few.  Imperfections,  indeed, 
affect  it,  but  they  are  of  purely  physical  occasion  and 
may  be  eliminated  or  accounted  for  as  well  by  another 
as  by  the  photographer  himself. 

In  trustworthiness,  then,  so  far  as  it  goes,  it  stands 
commended;  not  so  much  may  be  said  of  its  ability. 
This  depends  upon  the  work  to  which  it  is  put.  In  cer- 
tain lines  it  asserts  preeminence ;  in  certain  others  it  is 
so  far  behind  as  to  be  out  of  the  race.  The  reason  for 
both  is  one  and  the  same,  for,  as  the  French  would 


CHAP,  xxii      THE   CANALS   PHOTOGRAPHED  273 

say :  It  has  the  faults  of  its  quality.  The  very  trait 
that  fits  it  for  one  function,  bars  it  from  the  other. 
This  excellence  is  that  by  which  the  tortoise  outstripped 
the  hare,  — a  plodding  perseverance.  Far  less  sensitive 
than  the  retina  the  dry  plate  has  one  advantage  over  its 
rival,  —  its  action  is  cumulative.  The  eye  sees  all  it  can 
in  the  twentieth  of  a  second ;  after  that  its  perception, 
instead  of  increasing,  is  dulled,  and  no  amount  of 
application  will  result  in  adding  more.  With  the  dry 
plate  it  is  the  reverse.  Time  works  for,  not  against  it. 
Within  limits,  themselves  long,  light  affects  it  through- 
out the  period  it  stands  exposed  and,  roughly  speaking, 
in  direct  ratio  to  the  time  elapsed.  Thus  the  camera 
is  able  to  record  stars  no  human  eye  has  ever  caught 
and  to  register  the  structure  of  nebulae  the  eye  tries  to 
resolve  in  vain. 

Where  illumination  alone  is  concerned  the  camera 
reigns  supreme;  not  so  when  it  comes  to  a  question 
of  definition.  Then  by  its  speed  and  agility  the  eye 
steps  into  its  place,  for  the  atmosphere  is  not  the 
void  it  could  be  wished,  through  which  the  light-waves 
shoot  at  will.  Pulsing  athwart  it  are  air- waves  of 
condensation  and  rarefaction  that  now  obstruct,  now 
further,  the  passage  of  the  ray.  By  the  nimbleness  of  its 
action  the  eye  cunningly  contrives  to  catch  the  good 
moments  among  the  poor  and  carry  their  message  to  the 
brain.  The  dry  plate  by  its  slowness  is  impotent  to 


274  MAES  AND   ITS   CANALS  CHAP,  xxn 

follow.  To  register  anything,  it  must  take  the  bad  with 
the  better  to  a  complete  confusion  of  detail.  For  the 
air-waves  throw  the  image  first  to  one  place  and  then 
to  another,  to  a  blotting  of  both. 

All  of  which  renders  the  stars,  where  lighting  counts 
for  so  much  and  form  for  so  little,  the  peculiar  province 
of  celestial  photography.  With  the  study  of  the  sur- 
faces of  the  planets  the  exact  contrary  is  the  case.  With 
most  of  them  illumination  is  already  to  be  had  in 
abundance ;  definition  it  is  that  is  desired.  What  suc- 
ceeds so  excellently  with  the  stars  is  here  put  to  it  to 
do  anything  at  all.  At  its  best,  the  camera  is  hopelessly 
behind  the  eye  when  it  comes  to  the  decipherment  of 
planetary  detail.  To  say  that  the  eye  is  ten  times  the 
more  perceptive  is  not  to  overstep  the  mark.  To  try, 
therefore,  here  to  supplant  the  eye  by  the  camera 
is  time  thrown  away. 

Of  scant  importance  to  the  expert  in  such  matters  as 
Mars,  there  is  a  side  of  the  subject  in  which  service 
might  be  hoped  of  it:  that  of  elementary  exposition. 
Congenitally  incapable  of  competing  with  the  eye  in 
discovery,  the  most  that,  by  any  possibility,  could  be 
looked  for  would  be  a  recording  of  the  coarser  details 
after  the  fact.  For  this  reason  it  had  long  been  a 
purpose  at  Flagstaff  to  photograph  some  at  least  of 
the  canals.  But  the  project  seemed  chimerical.  To 
get  an  image  suitable  at  all  some  seconds  of  exposure 


CHAP,  xxn      THE   CANALS  PHOTOGRAPHED  275 

would  be  required,  and  during  such  time  the  shifting 
air-waves  would  blur  the  very  detail  desired  to  be  got. 
It  was  a  problem  of  essential  premises  mutually  anni- 
hilative.  The  more  the  would-be  photographer  should 
avoid  the  one,  the  more  he  would  fall  into  the  other. 
Nevertheless  the  thing  was  tried  in  1901.  In  1903 
the  subject  was  taken  up  by  Mr.  Lampland,  then  new 
at  the  observatory.  The  results  were  better  than 
those  of  two  years  before,  the  images  more  clear-cut 
but  still  incommunicable  of  canals.  Still  they  were 
satisfactory  enough  to  spur  to  increased  endeavor,  and 
during  the  following  interopposition  preparations  were 
made  to  grapple  with  the  planet  as  successfully  as  could 
be  devised  at  its  next  return.  This  happened  in 
May,  1905.  It  then  showed  a  disk  only  17"  in  diam- 
eter, or  yj^  of  that  of  the  moon,  —  and  this  disk  Mr. 
Lampland  attacked  with  the  24-inch  and  a  nega- 
tive amplificator  that  increased  the  focal  length  of  the 
former  to  143  feet.  At  such  focus  the  planet's  image 
was  received  upon  the  plate.  Everything  that  could 
conduce  to  success  had  been  put  in  requisition.  To 
this  end  of  better  definition  the  color  curve  of  the  ob- 
jective was  first  got,  and  for  it  a  special  color  screen 
constructed  by  Wallace.  In  spite  of  its  name  no  achro- 
matic is  so  in  fact,  but  brings  rays  of  different  tint  to 
different  focus.  The  color  curve  shows  where  these 
severally  lie,  and  the  color  screen, » a  chemically  tinted 


276  MARS  AND  ITS   CANALS  CHAP,  xxn 

piece  of  glass,  is  to  absorb  all  those  which  would  blur 
the  image  by  having  a  different  focus  from  the  ones  re- 
tained. Next,  all  manner  of  plates  were  tried.  For 
in  these  again  it  was  necessary  to  reconcile  two  con- 
tradictory characters,  a  rapid  plate  and  a  well- 
defining  one.  For  the  coarser  the  grain  the  speedier 
the  plate;  and  coarse  grain  disfigures  the  detail. 
Both  qualities  on  so  small  an  image  were  obligatory 
and  yet  both  could  not  be  got.  Then  the  clock 
had  to  be  as  smooth-running  as  possible.  So  by  a  sug- 
gestion of  Mr.  CogshalFs  one  was  obtained  that  filled 
this  requisite,  a  new  form  of  conical  pendulum.  Upon 
this  a  further  refinement  was  practiced.  Ordinarily 
clockwork  is  timed  to  follow  the  stars ;  this  was  altered 
to  follow  the  planet,  and  so  keep  it  more  nearly  mo- 
tionless while  its  picture  was  being  taken.  Then  the 
device  of  capping  down  the  telescope  to  suit  the  air- 
waves, which  had  been  found  so  effective  to  the  bringing 
out  of  fine  detail,  was  put  in  practice.  Lastly,  all  de- 
velopers were  tried,  and  those  found  suited  to  the 
finest  work  were  used. 

Many  pictures  were  taken  on  each  plate  one  after 
the  other,  both  to  vary  the  exposure  and  to  catch  such 
good  moments  as  might  chance.  Seven  hundred  images 
were  thus  got  in  all ;  the  days  of  best  definition  alone 
being  utilized.  The  eagerness  with  which  the  first 
plate  was  scanned  as  it  emerged  from  its  last  bath  may 


CHAP,  xxn      THE   CANALS  PHOTOGRAPHED  277 

be  imagined,  and  the  joy  when  on  it  some  of  the  canals 
could  certainly  be  seen.  There  were  the  old  configura- 
tions of  patches,  the  light  areas  and  the  dark,  just 
as  they  looked  through  the  telescope,  and  never  till 
then  otherwise  seen  of  human  eye,  and  there  more  mar- 
velous yet  were  the  grosser  of  those  lines  that  had  so 
piqued  human  curiosity,  the  canals  of  Mars.  He  who 
ran  might  now  read,  so  that  he  had  some  acquaintance 
with  photography.  By  Mr.  Lampland's  thought,  as- 
siduity, and  skill,  the  seemingly  impossible  had  been 
done. 

After  the  initial  success  was  thus  assured,  plates  were 
taken  at  other  points  around  the  planet  and  other  well- 
known  features  came  out;  "continents"  and  "seas," 
"canals"  and  "oases,"  the  curious  geography  of  the 
planet  printed  for  the  first  time  by  itself  in  black  and 
white.  By  chance  on  one  of  the  plates  a  temporal 
event  was  found  registered  too,  the  first  snowfall  of  the 
season,  the  beginning  of  the  new  polar  cap,  seen  visually 
just  before  the  plate  happened  to  be  put  in  and  repro- 
duced by  it  unmistakably.  Upon  the  many  images 
thirty-eight  canals  were  counted  in  all,  and  one  of  them, 
the  Nilokeras,  double.  Thus  did  the  canals  at  last 
speak  for  their  own  reality  themselves. 


PART  III 

THE  CANALS   IN  ACTION 


CHAPTER  XXIII 

CANALS:  KINEMATIC 

OO  far  in  our  account  of  the  phenomena  we  have 
regarded  the  lines,  the  spots,  and  everything  that 
is  theirs  solely  from  the  point  of  view  of  their  appearance 
at  any  one  time.  In  other  words,  we  have  viewed 
them  only  from  a  static  standpoint.  In  this  we  have 
followed  the  course  of  the  facts,  since  in  this  way  were 
the  canals  first  observed.  We  now  come  to  a  different 
phase  of  the  matter,  —  the  important  disclosure,  with 
continued  looking,  that  these  strange  things  show  them- 
selves to  be  subject  to  change.  That  is,  they  take 
on  a  kinematic  character.  This  at  once  opens  a  fresh 
field  of  inquiry  concerning  them  and  widens  the  horizon 
of  research.  It  increases  the  complexity  of  the  prob- 
lem, but  at  the  same  time  makes  it  more  determinate. 
For  while  it  greatly  augments  the  number  of  facts 
which  must  be  collected  toward  an  explanation  of 
what  the  things  are,  these  once  acquired,  it  narrows 
the  solution  which  can  apply  to  them. 

The  fact  of  change  in  the  Martian  markings  forces 
itself  upon  any  one  who  will  diligently  study  the  planet. 
He  will  be  inclined  at  first  to  attribute  it  to  observa- 

281 


282  MARS  AND  ITS   CANALS  CHAP,  xxm 

tional  mistakes  of  his  own  or  his  predecessor's  making, 
preferably  the  latter.  But  eventually  his  own  delinea- 
tions will  prove  irreconcilable  with  one  another,  and 
he  will  then  realize  the  injustice  of  his  inference  and 
will  put  the  cause,  where  indeed  it  rightly  belongs,  on 
the  things  themselves.  Confronted  by  this  fact  he  will 
the  more  fully  appreciate  how  long  and  systematic 
must  be  the  study  of  him  who  would  penetrate  the 
planet's  peculiarity.  Just  as  the  recognition  of  some- 
thing akin  to  seasonal  change  came  to  Schiaparelli,  be- 
cause of  his  attending  to  the  planet  with  an  assiduity 
unknown  to  his  predecessors;  so  it  became  evident 
that  to  learn  the  laws  of  these  changes  and  from 
them  the  meaning  of  the  markings,  there  was  necessary 
as  full  and  as  continuous  a  record  of  them  as  it  was  pos- 
sible to  obtain.  For  this  end  it  was  not  enough  to  get 
observations  from  time  to  time,  however  good  these 
might  be,  but  to  secure  as  nearly  as  might  be  a  complete 
succession  of  such,  day  after  day,  month  after  month, 
and  opposition  after  opposition.  The  outcome  justified 
the  deduction.  And  it  is  specially  gratifying  to  realize 
that  to  no  one  have  the  method  and  the  results  thus 
obtained  appealed  with  more  force  than  to  Schiaparelli 
himself. 

Perseverance  in  scanning  the  disk  long  after  the 
casual  observer  had  considered  it  too  far  away  for 
observational  purposes,  resulted  in  Schiaparelli's  detec- 


CHAP.XXIH  CANALS:   KINEMATIC  283 

tion  of  the  canals,  and  this  through  a  characteristic 
of  theirs  destined  to  play  a  great  part  in  their  history, 
their  susceptibility  to  change.  He  tells  us  in  his  Me- 
moria  I  how  Aeria  and  the  adjoining  regions  showed 
blank  of  any  markings  while  the  planet  was  near  in  1877 
and  the  disk  large  and  well  shown,  and  then  how,  to  his 
surprise,  as  the  planet  got  farther  away  and  the  disk 
shrank,  lines  began  to  come  out  in  the  region  with  un- 
mistakable certainty.  Thus  to  the  very  variability 
which  had  hidden  them  to  others  was  due  in  Schia- 
parelli's  hands  their  initial  recognition. 

Flux  affecting  the  canals  was  apparent  from  the 
outset  of  my  own  observations.  No  less  the  subject 
of  transformation  than  the  large  dark  regions  was  the 
network  of  tenuous  lines  that  overspread  them.  At 
times  they  were  very  hard  to  make  out,  and  then  again 
they  were  comparatively  easy.  Distance,  instead 
of  rendering  them  more  difficult,  frequently  did  the 
reverse.  Nor  was  the  matter  one  of  veiling.  Neither 
our  own  atmosphere  nor  that  of  Mars  showed  itself 
in  any  way  responsible  for  their  temporary  disappear- 
ance. It  was  not  always  when  our  atmospheric  con- 
ditions were  best  that  the  lines  stood  out  most  clearly, 
and  as  to  Martian  meteorology  there  was  no  sign  that 
it  had  anything  whatever  to  do  with  the  obliteration. 
Long  before  the  canals  were  dreamt  of,  veiling  by 
Martian  clouds  or  mist  had  been  considered  the  cause 


284  MARS  AND   ITS   CANALS  CHAP,  xxm 

of  those  changes  in  the  planet's  general  features,  which 
are  too  extensive  and  deep-toned  wholly  to  escape  ob- 
servation even  though  none  too  clearly  seen.  It  was 
early  evident  to  me  that  they  were  not  the  cause  of 
general  topographic  change,  and  equally  clearly  as 
inoperative  in  those  that  affected  the  canals.  In  short, 
nothing  extrinsic  to  the  canal  caused  its  disappearance ; 
whatever  the  change  was,  its  action  lay  intrinsic  to  the 
canal  itself. 

On  occasion  canals  in  whole  regions  appeared  to  be 
blotted  out.  The  most  careful  scrutiny  would  fail 
to  disclose  them,  where  some  time  before  they  had  been 
perfectly  clear.  And  this  though  distance  was  at  its 
minimum  and  definition  at  its  best.  Even  the  strongest 
marked  of  the  strange  pencil  lines  would  show  at  times 
only  as  ghosts  of  their  former  selves,  while  for  their  more 
delicate  companions  it  taxed  one's  faith  to  believe  that 
they  could  ever  really  have  existed.  Illumination 
was  invoked  to  account  for  this,  and  plays  a  part  in  the 
effect  undoubtedly.  For  at  plumb  opposition  the  cen- 
tre of  the  disk  for  two  or  three  years  has  shown  less 
detail  than  before  and  after  that  event.  This  is  prob- 
ably due  not,  as  with  the  moon,  to  the  withdrawal  of 
shadows,  but  to  the  greater  glare  to  which  the  disk 
is  then  subjected.  But  this  is  not  the  chief  cause  of 
the  change. 

Still  more  striking  and  unaccountable  was  the  fact 


CHAP.   XX1I1 


CANALS:    KINEMATIC 


285 


Showing  seasonal  change. 
I. 

The    increase    of    the 


that  each  canal  had  its  own  times  and  seasons  for  show- 
ing or  remaining  hid.  Each  had  its  entrances  upon  the 
scene  and  its  exits  from  it. 
What  dated  the  one  left 
another  unaffected.  The 
Nilokeras  was  to  be  seen 
when  the  Chrysorrhoas  was 
invisible,  and  the  Jamuna 
perfectly  evident  when  the 
Indus  could  scarcely  be 
made  out. 

So  much  shows  in  the  two 
drawings  here  reproduced. 
Ganges  and  the  advent  of  the  Chrysorrhoas  are 
noticeable  in  the  second 
over  the  first. 

Seasonal  changes  seemed 
the  only  thing  to  account 
for  the  phenomena.  And  in 
a  general  sense  this  was 
undoubtedly  the  explana- 
tion. To  learn  more  about 
the  matter,  to  verify  it  if  it 
existed,  and  to  particularize 
it  if  possible,  I  determined  to  undertake  an  investiga- 
tion permitting  of  quantitative  precision  in  the  case. 
A  method  of  doing  this  occurred  to  me  which  would 


Showing  seasonal  change. 
II. 


286  MARS  AND  ITS  CANALS  CHAP,  xxm 

yield  results  deserving  of  consideration  from  the  amount 
of  data  upon  which  each  was  based  and  capable 
of  being  compared  with  one  another  upon  an  equal 
footing  from  which  relative  information  could  be  de- 
rived. It  seemed  wise  to  determine  from  the  draw- 
ings the  degree  of  visibility  of  a  given  canal  at 
different  seasons  of  the  Martian  year,  and  then  to  do 
this  for  every  important  canal  during  the  same  period 
of  time.  The  great  number  of  the  drawings  suggested 
this  use  to  which  they  might  be  put.  For  from  a  great 
accumulation  of  data  a  set  of  statistics  on  the  subject 
could  be  secured  in  which  accident  or  bias  would  be 
largely  eliminated  and  the  telling  effect  of  averages 
make  itself  felt. 

To  render  this  possible  it  was  necessary  that  the 
drawings  should  be  alike  numerous,  consecutive,  and 
extended  in  time.  These  conditions  were  fulfilled  by 
the  drawings  made  by  me  at  the  opposition  of  1903. 
Three  hundred  and  seventy-two  drawings  had  then 
been  secured,  and  they  covered  between  them  a  period 
of  six  months  and  a  half.  They  were  also  as  consecu- 
tive as  it  was  possible  to  secure.  During  a  part  of  the 
period  the  planet  was  seen  and  drawn  at  every  twenty- 
four  hours,  from  April  5,  namely,  to  May  26,  or  for  forty- 
six  consecutive  days.  Though  the  rest  of  the  time  did 
not  equal  this  perfection,  no  great  gap  occurred,  and 
one  hundred  and  forty-three  nights  were  utilized  in  all. 


CHAP,  xxin  CANALS:    KINEMATIC  287 

Furthermore,  as  these  drawings  were  all  made  by  one 
man,  the  personal  equation  of  the  observer  —  a  very 
important  source  of  deviation  where  drawings  are  to 
be  compared  —  was  eliminated. 

But  even  this  does  not  give  an  idea  of  the  mass  of 
the  data.  For  by  the  method  employed  about 
100  drawings  were  used  in  the  case  of  each  canal, 
and  as  109  canals  were  examined  this  gave  10,900 
separate  determinations  upon  which  the  ultimate 
result  depended.  That  each  of  these  determinations 
was  independent  of  the  others  will  appear  from  a 
description  of  the  method  itself  on  which  the  investiga- 
tion was  conducted.  To  understand  that  method  one 
must  begin  a  little  way  back. 

As  the  two  planets,  Mars  and  the  Earth,  turn  on  their 
axes  the  parts  of  their  surfaces  they  present  to  each 
other  are  constantly  changing.  For  a  feature  on  Mars 
to  be  visible  from  a  given  post  on  earth,  observer  and 
observed  must  confront  each  other,  and,  furthermore, 
it  must  be  day  there  when  it  is  night  here.  But,  as 
Mars  takes  about  forty  minutes  longer  to  turn  than  the 
Earth,  such  confronting  occurs  later  and  later  each 
night  by  about  forty  minutes,  until  finally  it  does  not 
occur  at  all  while  Mars  is  suitably  above  the  horizon; 
then  the  feature  passes  from  sight  to  remain  hidden 
till  the  difference  of  the  rotations  brings  it  round  into 
view  again.  There  are  thus  times  when  a  given  region 


288  MARS   AND   ITS   CANALS  CHAP,  xxm 

is  visible,  times  when  it  is  not,  and  these  succeed  each 
other  in  from  five  to  six  weeks,  and  are  called  presenta- 
tions. For  about  a  fortnight  at  each  presentation  a 
region  is  centrally  enough  placed  to  be  well  seen;  for 
the  rest  of  the  period  either  ill-placed  or  on  the  other 
side  of  the  planet. 

If  a  marking  were  always  salient  enough  it  would 
appear  in  every  drawing  made  of  the  disk  during  the 
recurrent  fortnights  of  its  display.  If  it  were  weaker 
than  this,  it  might  appear  on  some  drawings  and  not  on 
others,  dependent  upon  its  own  strength  and  upon  the 
definition  at  the  moment,  and  we  should  have  a  certain 
percentage  of  visibility  for  it  at  that  presentation. 
While  if  it  changed  in  strength  between  one  presentation 
and  the  next,  the  percentage  of  its  recording  would 
change  likewise.  Definition  of  course  is  always  vary- 
ing, but  if  its  value  be  noted  at  the  time  of  each  draw- 
ing this  factor  may  be  allowed  for  more  or  less  success- 
fully. Making  such  allowance,  together  with  other 
corrections  to  produce  extrinsic  equality,  such  as  the 
planet's  distance,  which  we  need  not  enter  upon  here, 
we  are  left  with  only  the  marking's  intrinsic  visibility 
to  affect  the  percentages ;  that  is,  the  percentages  tell 
of  the  changes  it  has  successively  undergone  and  give 
us  a  history  of  its  wax  and  wane. 

From  drawings  accurately  made  it  is  possible  to  add 
to  the  accuracy  of  the  percentage  by  noting  in  each, 


CHAP,  xxiu  CANALS :    KINEMATIC  289 

not  only  the  presence  or  absence  of  the  marking,  but 
the  degree  of  strength  with  which  it  is  represented. 
This  was  done  on  the  final  investigation  in  the  present 
case,  and  it  was  interesting  to  note  how  little  difference 
it  made  in  the  result. 

The  longitude  of  each  canal  was  known,  and  the 
longitude  of  the  central  meridian  of  each  drawing  was 
always  calculated  and  tabulated  with  the  drawing,  so 
that  it  was  possible  to  tell  which  drawings  might  have 
shown  the  canal.  Only  when  the  position  of  the  canal 
was  within  a  certain  number  of  degrees  of  the  centre 
of  the  drawing  (60°)  was  the  drawing  used  in  the 
result,  allowance  being  duly  made  for  the  loss  upon  the 
phase  side.  Each  drawing,  it  should  be  remembered, 
was  as  nearly  an  instantaneous  picture  of  the  disk  as 
possible.  It  covered  only  a  few  minutes  of  observa- 
tion, and  was  made  practically  as  if  the  observer  had 
never  seen  the  planet  before.  In  other  words,  the 
man  was  sunk  in  the  manner.  Such  mental  effacement 
is  as  vital  to  good  observation  as  mental  assertion  is 
afterward  to  pregnant  reasoning.  For  a  man  should 
be  a  machine  in  collecting  his  data,  a  mind  in  coordi- 
nating them.  To  reverse  the  process,  as  is  sometimes 
done,  is  not  conducive  to  science. 

When  the  successive  true  percentages  of  visibility 
of  a  given  canal  had  thus  been  found,  they  were  plotted 
vertically  at  points  along  a  horizontal  line  correspond- 


290  MARS  AND  ITS   CANALS  CHAP,  xxm 

ing  in  distance  from  the  origin  to  the  number  of  days 
after  (or  before)  the  summer  solstice  of  the  Martian 
northern  hemisphere.  The  horizontal  distance  thus 
measured  the  time  while  the  vertical  height  gave  the 
relative  visibility.  The  points  so  plotted  were  then 
joined  by  a  smooth  curve.  This  curve  reproduced  the 
continuous  change  in  visibility  undergone  by  the  canal 
during  the  period  under  observation.  It  gave  a 
graphic  picture  of  the  canal's  change  of  state.  It 
seemed,  therefore,  proper  to  call  it  the  canal's  cartouche 
or  sign  manual. 

In  this  manner  were  obtained  the  cartouches  of  109 
canals.  Now,  as  the  presence  or  absence  of  any  canal 
in  any  drawing  was  entirely  irrespective  of  the 
presence  or  absence  of  another,  each  such  datum 
spoke  only  for  itself,  and  was  an  entirely  independent 
observation.  The  whole  investigation  thus  rested  on 
10,900  completely  separate  determinations,  each  as 
unconditioned  by  the  others  as  if  it  existed  alone. 

As  every  factor  outside  of  the  canal  itself  which  could 
affect  the  latter's  visibility  was  taken  account  of,  and 
the  correction^  due  to  it  as  nearly  as  possible  applied 
before  the  cartouches  were  deduced,  the  latter  repre- 
sent the  visibility  of  the  canal  due  to  intrinsic  change 
alone.  In  other  words,  they  give  not  the  apparent  only 
but  the  real  history  of  the  canal  for  the  period  con- 
cerned. 


CHAP,  xxin  CANALS:   KINEMATIC  291 

Important  disclosures  result  from  inspection  of  the 
cartouches.  This  we  shall  perceive  by  considering  what 
different  curves  mean  in  the  case.  If  the  canal  were 
an  unchangeable  phenomenon,  for  any  reason  what- 
ever, its  cartouche  would  be  a  straight  line  parallel  to 
the  horizon  of  the  diagram.  This  is  evident  from  the 
fact  that  the  visibility  would  then  never  vary.  If, 
on  the  other  hand,  it  were  waxing  and  waning,  and  the 
wax  or  wane  were  uniform,  the  cartouche  would  be  a 
straight  line  inclined  to  the  horizontal;  rising  if  the 
canal  were  increasing,  falling  when  it  decreased. 
Lastly,  if  the  rate  of  change  itself  varied,  the  cartouche 
would  be  a  curve  concave  or  convex  to  the  line  denot- 
ing the  time,  according  as  the  rate  of  change  of  the 
growth  or  decay  grew  greater  or  less. 

To  see  this  the  more  clearly,  we  may  set  over  against 
the  cartouche  the  canal  character  it  signalizes :  — 

CARTOUCHE.  CHARACTER. 

A  horizontal  straight  line.  Canal  invariable, 

A  straight  line  tilted  up  on  the  right.  Canal  ifieTreasing  steadily. 

A  straight  line  tilted  up  on  the  left.  Canal  decreasing  steadily. 

A  curved  line  descending,  concave  from  Canal  decreasing,  but  more 

above.  and  more  slowly. 

A  curved  line  ascending,  concave  from  Canal  increasing,  but  more 

above.  and  more  rapidly. 

A  curved  line  descending,  convex  from  Canal  decreasing  more  and 

above.  more  rapidly. 

A  curved  line  ascending,  convex  from  Canal  increasing  more  and 

above.  more  slowly. 


292  MAKS   AND  ITS  CANALS  CHAP,  xxm 

CARTOUCHE.  CHARACTER. 

A  curved  line  first  descending,  then  Canal  decreasing  more  and 
ascending,  concave  from  above  more  slowly  to  a  mini- 
throughout.  mum,  thence  increasing 

more  and  more  rapidly. 

A  curved  line  first  descending,  then  Canal  increasing  more  and 
ascending,  convex  from  above  more  slowly  to  a  maxi- 
throughout.  mum,  thence  decreasing 

more  and  more  rapidly. 

If  the  cartouche  first  falls  and  then  rises,  this  shows 
the  canal  to  have  passed  through  a  minimum  state  at 
the  time  denoted  by  the  point  of  inflection;  if  it  rises 
first  and  falls  afterward,  this  betokens  in  the  same  way 
a  maximum.  Thus  the  cartouches  reveal  to  us  the 
complete  history  of  the  canals,  —  what  changes  they 
underwent  and  the  times  at  which  these  occurred. 
The  cartouche,  then,  is  the  graphic  portrayal  of  the 
canal's  behavior.  It  not  only  distinguishes  at  once 
between  the  dead  and  the  living,  as  we  may  call  the 
effect  of  intrinsic  change,  but  it  tells  the  exact  character 
of  this  change,  —  the  way  it  varied  from  time  to  time, 
the  epoch  at  which  the  development  was  at  its  minimum 
or  its  maximum  for  any  given  canal,  and  lastly,  its 
actual  strength  at  any  time,  thus  giving  its  relative 
importance  in  the  canal  system.  For  the  height  of  the 
curve  above  the  diagrammatic  horizon  marks  the  abso- 
lute as  well  as  the  relative  visibility  and  enables  us  to 
rank  the  canals  between  themselves. 

Now,  the  first  point  it  furnishes  a  criterion  for  is  the 


CHAP,  xxin  CANALS:   KINEMATIC  293 

real  or  illusory  character  of  the  canals.  If  a  line  be  due 
to  illusion,  whether  optical  or  physical,  it  can  vary  only 
from  extrinsic  cause,  since  it  has  no  intrinsic  existence. 
If,  therefore,  all  extrinsic  cause  be  allowed  for,  the  car- 
touche of  this  ghost  must  needs  be  a  horizontal  straight 
line.  Even  if  the  extrinsic  factors  to  its  production 
be  imperfectly  accounted  for,  their  retention  could  only 
cause  systematic  variations  from  the  straight  line  in  all 
the  lines,  which  would  themselves  vary  systematically, 
and  these  factors  could  therefore  be  detected. 

This  criterion  is  absolute.  Unless  all  the  cartouches 
were  approximately  straight  lines,  no  illusion  theory 
of  any  kind  whatever  could  explain  the  facts.  Even 
then  the  lines  might  all  be  real ;  for  unchangeable  reality 
would  produce  the  same  effect  on  the  cartouches  as  illu- 
sion. In  the  case  therefore  of  horizontal  straight  line 
cartouches,  we  should  have  no  guarantee  on  that  score 
of  reality  or  illusion ;  but,  on  the  other  hand,  curves  or 
inclined  straight  lines  in  them  would  be  instantly  fatal 
to  all  illusion  theories. 

Turning  now  to  the  109  cartouches  obtained  in  1903, 
the  first  point  to  strike  one's  notice  is  that  all  but  three 
of  them  are  curves  and  that  even  these  three  must  be 
accepted  with  a  caveat.  Here,  then,  the  cartouches  dis- 
pose once  and  for  all  of  any  and  every  illusion  theory. 
They  show  conclusively  that  the  canals  are  real  objects 
which  wax  and  wane  from  some  intrinsic  cause. 


294  MARS  AND  ITS  CANALS  CHAP,  xxm 

The  second  result  afforded  by  the  cartouches  is  not  of 
a  destructive,  negative  character,  —  however  valuable 
the  destruction  of  bars  to  knowledge  may  be,  —  but  of 
a  constructive,  positive  one.  It  does  not,  like  the  first, 
follow  from  mere  inspection,  but  is  brought  to  light  only 
by  comparison  of  all  the  cartouches.  In  a  positive  way, 
therefore,  its  testimony  is  as  conclusive  as  it  was  in  a  neg- 
ative direction.  For  that  10,900  separate  and  independ- 
ent data  should  result  in  a  general  law  of  development 
through  either  conscious  or  unconscious  bias,  when  those 
data  would  have  to  be  combined  in  so  complicated  a 
manner  for  the  result  to  emerge  as  is  here  the  case,  is 
impossible.  Chance  could  not  do  it  and  consciousness 
would  require  a  coordinate  memory,  to  which  Murphy's 
nine  games  of  chess  at  once  would  be  child's  play. 

Of  the  109  canals  examined  106  showed  by  their  car- 
touches that  they  had  been  during  the  whole  or  a  part 
of  the  period  in  a  state  of  change.  But  the  change 
was  not  the  same  for  all.  In  some  the  minimum  came 
early ;  in  others,  late.  Some  decreased  to  nothing  and 
stayed  there;  others  increased  from  zero  and  were 
increasing  still  at  the  time  observations  closed. 

Latitude  proved  the  means  of  bringing  comparative 
order  out  of  the  chaos.  When  the  canals  were  ranged 
according  to  their  latitude  on  the  planet,  a  law  in  their 
development  came  to  light.  To  understand  it,  the 
circumstances  under  which  the  canals  were  presented 


CHAP.   XXIII 


CANALS:   KINEMATIC 


295 


must  be  considered  as  regards  the  then  season  of 
the  planet's  year.  In  1903  the  planet  passed  on 
February  28  through  the  point  of  its  orbit  where  the 
summer  solstice  of  the  northern  hemisphere  occurs. 
One  hundred  and  twenty-six  days  later  took  place  the 
first  snowfall  in  the  arctic  and  subarctic  regions,  an 
event  that  denoted  the  beginning  of  the  new  polar  cap ; 
from  which  date  the  snow  there  gradually  increased. 
Its  autumnal  equinox  the  planet  did  not  reach  till 
August  29.  Now,  the  canals  were  observed  from  thirty- 
six  days  before  the  summer  solstice  of  the  northern 
hemisphere  to  one  hundred  and  forty-seven  days  after 
that  event.  We  may  tabulate  the  dates  as  follows  :  — 


DAY   FROM 
SUMMER  SOLSTICE 

VERNAL 
LONGITUDE 

CORRESPONDING 
DATE   ON   EARTH 

-30 

77° 

June  9 

0 

90° 

June  22 

+  30 

103° 

July  6 

-f  60 

117° 

July  20 

+  90 

131° 

August  4 

+  120 

146° 

August  20 

+  150 

162° 

September  5 

The  vernal  longitude  is  the  longitude  of  the  planet 
in  its  orbit  reckoned  from  the  vernal  equinox.  From 
the  table  it  appears  that  the  cartouches  cover  the  de- 
velopment of  the  canals  from  about  June  6  to  September 
1  of  the  Martian  northern  hemisphere  for  the  current 
but  to  us  undated  year,  ab  Marie  condita. 


296 


MAKS   AND  ITS   CANALS 


CHAP.  XXIII 


The  109  canals  included  all  the  more  conspicuous 
canals  on  the  planet  at  that  opposition,  all  those 
that  lent  themselves  by  the  sufficient  frequency 
with  which  they  were  seen  to  a  statistical  result. 
They  lay  spread  all  the  way  between  the  edge  of 
the  polar  cap  in  latitude  87°  north  to  the  extreme 
limit  south,  at  which  the  then  tilt  of  the  north  pole 
toward  the  earth  permitted  of  canal  recognition. 
This  southern  limit  was  in  about  latitude  35°  south. 
Farther  south  than  this  vision  became  too  oblique, 
amounting  as  it  did,  with  an  adverse  tilt  of  twenty- 
five  degrees  to  start  with,  to  something  over  sixty 
degrees,  for  detection  of  such  fine  markings  to  be 
possible.  Between  the  two  limits  thus  imposed,  by 
the  perpetual  snow  on  the  one  side  and  the  ob- 
servational tilt  on  the  other,  the  109  canals  were 
distributed  by  zones  as  follows :  — 


ZONE 

LATITUDE 

NUMBER  OF 
CANALS 

North  Polar 

87°  N.-780  N. 

1 

Arctic 

78°  N.-660  N. 

9 

Sub-Arctic 

66°  N.-510  N. 

9 

North  Temperate 

51°  N.-370  N. 

11 

North  Sub-Tropic 

37°  N.-240  N. 

18 

North  Tropic 

24°  N.-120  N. 

21 

North  Equatorial 

12°  N.-  0°  N. 

14 

South  Equatorial 

0°  N.-120  S. 

17 

South  Tropic 

12°  S.-240  S. 

7 

South  Sub-Tropic 

24°  S.-37°S. 

2 

CHAP,  xxin  CANALS:   KINEMATIC  297 

As  the  latitude  of  a  canal  in  the  investigation  was 
taken  as  that  of  its  mid-point,  such  being  the  mean 
value  of  its  successive  parts,  the  latitudes  about  which 
information  was  obtained  lay  within  the  limits  given 
above,  the  most  northern  canal,  the  Jaxartes  N  having 
for  its  mid-latitude  78°  north,  and  the  most  southern, 
the  Nectar,  that  of  27°  south. 

The  zones  comprised  each  a  belt  of  territory  about 
thirteen  degrees  wide,  the  first  being  less  solely  because 
in  part  occupied  by  the  permanent  polar  cap. 

The  curves  of  all  the  canals  in  a  given  zone  have  been 
combined  into  a  mean  curve  or  cartouche  for  that 
zone;  and  then  the  cartouches  for  the  several  zones 
have  been  represented  and  ranged  according  to  lati- 
tude on  the  accompanying  plate.  Consideration  of 
these  mean  canal  cartouches  is  very  instructive.  In 
the  first  place  not  one  of  them  is  a  straight  line,  either 
horizontal  or  inclined.  All  are  curves  and,  with  the 
exception  of  the  top  one,  all  show  a  minimum  or  lowest 
point  during  the  period  under  observation.  From  this 
point  they  rise  with  the  time,  or  to  the  right  on  the 
plate.  A  black  star  marks  this  minimum,  and  is  found 
farther  and  farther  to  the  right  as  one  goes  down  the 
plate ;  that  is,  as  one  travels  from  the  neighborhood  of 
the  arctic  regions  down  to  the  equator  and  then  over 
into  the  planet's  southern  hemisphere.  Drawing  now 
a  line  approximately  through  the  stars  and  remembering 


298 


MAKS   AND   ITS   CAXALS 


CHAP.   XXIII 


CHAP.    XXIII 


CANALS:   KINEMATIC  299 


that  the  minimum  means  the  date  at  which  the  canal 
started  to  develop,  we  see  that  the  canal  development 
began  at  the  border  of  the  north  polar  cap  and  thence 
continued  down  the  disk  over  the  planet's  surface,  as 
far  as  observation  permitted  the  surface  to  be  seen, 
which  was  some  thirty-five  degrees  into  the  other  hemi- 
sphere. This  is  the  first  broad  fact  disclosed  by  the 
cartouches. 

Furthermore,  the  development  took  place  at  an 
approximately  uniform  rate.  This  is  shown  by  the 
fact  that  the  line  passing  through  the  black  stars  is 
approximately  straight;  for  such  straightness  means 
that  progression  down  the  disk  as  measured  by  the 
latitude  bore  throughout  the  same  ratio  to  the  time 
elapsed. 

Looking  at  them  again  we  notice  that  the  three  top- 
most cartouches,  those  of  the  north  polar,  arctic,  and 
sub-arctic  canals  respectively,  dip  at  the  right  before 
the  end  of  the  observations,  while  the  other  seven  were 
still  rising  when  those  observations  were  brought  to  a 
close.  A  reason  for  this,  or  at  least  a  significant  coin- 
cidence, is  to  be  found  in  the  dotted  line  pendent  from 
the  top  of  the  table  and  labelled  "First  Frosts."  This 
dotted  line  denotes  the  date  at  which  the  first  extensive 
frost  occurred  in  the  polar  regions;  for  even  before 
this  time  patches  of  white  had  appeared  north  of  the 
Mare  Acidalium,  denoting  the  on-coming  of  the  cold. 


300  MARS  AND  ITS   CANALS  CHAP,  xxm 

The  frost  did  not  last  but  came  and  went  and  came 
again  just  as  it  does  on  earth,  growing  more  insistent 
and  long-lived  at  each  fresh  fall.  Its  sphere  of  opera- 
tion was  confined  to  the  three  zones  in  question. 
Even  these  zones  it  by  no  means  covered,  merely 
blotching  them  in  places  with  fungi-like  patches  of  frost. 
Beyond  them  south  it  never  extended  during  the  period 
of  the  observations ;  indeed,  it  hardly  entered  the  sub- 
arctic zone  at  all  at  this  very  beginning  of  the  polar 
winter.  For  it  was  only  August  20  then.  The  coin- 
cidence of  the  isotherm  as  betrayed  by  the  deposition 
of  frost  with  the  dividing  line  between  the  canal- 
development  curves  that  dip  down  at  this  season  and 
those  that  still  continue  to  rise  is  suggestive. 

It  becomes  all  the  more  so  when  the  three  cartouches 
are  considered  seriatim.  The  most  polewards,  the 
north  polar  one,  had  sunk  to  zero  sometime  before  the 
first  extensive  frost  occurred;  the  second,  the  arctic, 
did  so  later  than  its  northern  neighbor,  probably  just 
before  the  epoch  in  question;  while  the  third,  prac- 
tically outside  the  zone  of  deposition,  was  behind  both 
the  others  in  its  descent.  Inspection  of  the  drawings 
upon  which  the  cartouches  are  based  confirms  an  infer- 
ence deduced  from  this :  that  it  was  cold  that  killed, 
not  frost  that  covered,  them,  which  was  responsible 
for  their  obliteration.  The  drawings  show  that  the 
canals  ceased  to  be  seen  before  the  white  patches  were 


CHAP,  xxm  CANALS:    KINEMATIC  301 

evident.  Now  this  would  be  the  exact  behavior  of 
vegetation.  It  would  be  killed,  turned  brown  by 
freezing,  and  so  rendered  invisible  to  us  against  its 
ochre  desert  background,  before  the  cold  had  grown 
intense  enough  to  cover  that  ground  with  a  solid  white 
carpet  of  frost.  At  the  opposition  of  1905,  however, 
the  extreme'northern  canals  were  visible  after  the  snow 
had  covered  all  the  country  about  them,  being  evident 
as  lines  threading  the  new  cap. 

These  three  cartouches  furthermore  show  each  a 
maximum,  and  what  is  significant  the  maximum  occurs 
later  in  time  for  each,  according  as  the  zone  lies  remote 
from  the  pole.  A  red  star  marks  this  maximum  and 
shows  that  the  time  of  greatest  development  for  the 
three  zones  was  respectively :  — 

41  days  after  fhe  summer  solstice  for  the  North  Polar. 

61  days  after  the  summer  solstice  for  the  Arctic. 

95  days  after  the  summer  solstice  for  the  Sub-Arctic. 

We  now  pass  to  the  other  curves,  those  that  were 
unaffected  by  cold.  Though  in  these  the  minima  them- 
selves show  the  law  of  latitudinal  progression,  the  wave- 
like  character  of  the  advance  is  even  better  disclosed 
by  the  curves.  As  the  eye  follows  them  down  the 
page,  the  advance  of  the  wave  to  the  right  is  plainly 
apparent.  The  slope  of  the  wave  is  much  the  same  for 
all,  implying  that  a  like  force  was  at  work  successively 
down  the  latitudes. 


302  MARS  AND  ITS   CANALS  CHA 

It  will  be  noticed  next  that  in  all  the  mean  car- 
touches the  gradient  is  greater  after  the  minimum 
than  before  it.  The  curves  fall  gently  to  their  lowest 
points  and  rise  more  steeply  from  them.  Such  profile 
indicates  that  the  effects  of  a  previous  force  were  slowly 
dying  out  down  to  the  minimum  and  that  then  an  im- 
pulse started  in  to  act  afresh.  This  explains  the  atti- 
tude of  the  canals  that  died  out.  In  them  the  effect 
of  the  old  force  shows  as  in  the  others,  but  no  impulse 
came  in  their  case  to  resuscitation. 

It  seems  possible  to  trace  this  force  to  an  origin  at 
the  south.  For  beginning  with  the  north  sub- tropic 
zone  the  gradient  on  the  left  shows  less  and  less  steep 
southward  to  the  south  sub-tropic  zone.  Such  a 
dying-down  swell  is  what  should  be  looked  for  in  an 
impulse  which  had  travelled  from  the  south  northward, 
since  the  wave  would  affect  the  more  northern  zones 
last,  and  less  of  a  calm  period  would  intervene  between 
the  two  impulses  from  opposite  poles. 

The  cartouches,  then,  state  that  the  canals  began  to 
develop  after  the  greatest  melting  of  the  polar  cap 
had  occurred;  that  this  development  proceeded  down 
the  latitudes  to  the  equator,  and  then  not  stopping 
there  advanced  up  the  latitudes  of  the  other  hemi- 
sphere. In  the  next  place  they  show  that  in  the 
arctic  region  the  development  was  arrested  and  devo- 
lution or  decay  set  in  as  it  began  to  get  cold  there, 


CHAP,  xxni  CANALS:    KINEMATIC  303 

the  most  northern  canals  being  affected  first.  Finally, 
that  a  similar  wave  of  evolution  had  occurred  from 
the  opposite  pole  some  time  before  and  had  then 
passed  away.  And  this  evidence  of  the  cartouches 
is  direct,  and  independent  of  any  theory. 


CHAPTER  XXIV 

CANAL   DEVELOPMENT 

Individually  Instanced 

A  S  an  interesting  instance  of  the  law  of  develop- 
-"-  ment  we  may  take  the  career  of  the  Brontes 
during  this  same  Martian  year;  the  Brontes  witness- 
ing individually  to  the  same  evolutionary  process  that 
the  canals  collectively  exhibit. 

The  Brontes  is  one  of  the  most  imposing  canals  upon 
the  planet.  It  is  not  so  much  its  length  which  renders 
it  a  striking  object,  though  this  length  is  enough  to 
entitle  it  to  consideration,  being  no  less  than  2440  miles. 
Its  direction  is  what  singles  it  out  to  notice,  for  it  runs 
almost  north  and  south.  For  this  reason  it  swings  into 
a  position  to  hold  the  centre  of  the  stage  for  a  time  with 
the  precision  of  a  meridian,  as  the  planet's  rotation 
turns  its  longitude  into  view.  The  points  which  it 
connects  help  also  to  add  to  its  distinction.  For  the 
Sinus  Titanum  at"  its  southern  end  and  the  Propontis 
at  its  northern  are  both  among  the  conspicuous  points 
of  the  disk.  The  latter  is  but  twelve  degrees  farther 
east  than  the  former,  while  it  is  sixty-six  degrees  farther 
north.  This  long  distance,  —  from  nearly  the  line  of  the 
tropics  in  the  southern  hemisphere  to  mid-temperate 

304 


CHAP,  xxn-  CANAL  DEVELOPMENT  305 

regions  of  the  northern,  —  the  canal  runs  in  an 
absolutely  straight  course. 

Its  north  and  south  character  commends  it  for  any 
investigation  of  canal  development,  since  it  runs  in  the 
general  direction  that  development  takes.  Its  great 
latitudinal  stretch  further  fits  it  for  a  recorder  of 
changes  sweeping  down  the  disk;  so  that  both  in  di- 
rection and  length  it  stands  well  circumstanced  for  a 
measure  of  latitudinal  variations.  The  fact  that  it  is 
usually  a  fairly  conspicuous  canal  does  not  detract  from 
its  virtue  in  this  respect.  It  was  first  recognized  at 
Flagstaff  in  1894.  But  once  realized,  so  to  speak,  it  was 
possible  to  identify  it  with  a  canal  seen  by  Schiaparelli 
and  supposed  by  him  to  be  the  Titan ;  indeed,  it  played 
hide  and  seek  with  that  canal  throughout  his  drawings. 
In  1894  both  it  and  the  Titan  were  so  well  seen  that  its 
separate  existence  was  unmistakable,  causing  it  to  be 
both  recognized  and  named.  It  is,  like  the  Titan,  one 
of  the  sheaf  of  canals  descending  the  disk  from  the 
Sinus  Titanum,  and  lies  just  to  the  east  of  the  Titan  in 
the  bunch.  In  1896  it  was  also  prominent;  and  at 
both  these  oppositions  most  so  from  its  southern  end, 
its  northern  one  being  more  or  less  indefinite,  especially 
in  1894. 

In  1901  it  was  not  the  same.  Instead  of  being  the 
conspicuous  canal  it  had  been  in  earlier  years,  it  was 
now  so  faint  as  with  difficulty  to  be  made  out.  It 


306  MAES   AND   ITS   CANALS  CHAP,  xxiv 

remained  so  to  the  close  of  observations.  It  was  now 
under  suspicion.  Its  behavior  in  1896-1897  had  led 
to  the  supposition  that  not  only  were  seasonal  changes 
taking  place  in  it,  but  that  those  changes  were  such  as 
to  point  to  a  law  in  the  case  with  which  its  conduct  in 
1901  fayed  in.  The  suspicion  did  not,  however,  be- 
come a  certainty  till  the  opposition  of  1903.  The  length 
of  time  during  which  the  disk  was  then  kept  under  scru- 
tiny resulted  in  the  method  of  its  metamorphosis  being 
discovered. 

At  the  very  start  of  observations  its  longitude  chanced 
to  be  nearly  central  and  it  was  made  out ;  but  so  far  off 
was  the  planet  that  only  its 
northern  part  could  be  de- 
tected, because,  as  after- 
ward appeared,  this  part 
was  the  stronger,  the  canal 
being  decidedly  inconspicu- 
ous, whereas  other  canals, 
the  northern  and  even  the 
Pallene  and  the  Dis,  were 
i.  February  25.  strongly  marked.  At  the 

next  presentation  the  planet  was  nearer,  and  details 
previously  hidden  for  the  distance  now  came  out. 
Among  them  was  the  Brontes,  which,  showing  better 
than  in  January,  could  be  traced  all  the  way  to  the 
Sinus  Titanum.  A  drawing  (I)  made  on  February  25 


CHAP.   XXIV 


CANAL   DEVELOPMENT 


307 


II.    March  30. 


and  reproduced  in  the  text  shows  its  appearance  at 
the  time.  Its  emergence  under  neared  conditions 
only  served  to  accentuate 
its  relative  inconspicuous- 
ness,  for  it  showed  now 
notably  inferior  to  the 
northern  canals,  and  this 
not  only  in  the  matter  of 
general  visibility,  but  in 
the  character  it  displayed. 
It  was  a  line  of  hazy  defi- 
nition, contrasting  thus 
with  the  sharp  dark  forms  of  its  northern  neighbors. 
As  the  planet  steadily  approached  the  earth,  and  the 
canals  to  the  north  became 
better  and  better  seen,  the 
Brontes  instead  of  sharing 
in  the  general  improve- 
ment did  exactly  the  op- 
posite. It  grew  less  visible 
when  it  should  have  grown 
more  so,  if  distance  had 
been  the  cause  of  its  ap- 
pearance. It  was  now 
only  to  be  seen  at  the  north,  even  when  it  was  seen 
at  all;  a  state  of  things  exemplified  in  Drawings  II 
and  III. 


III.    Aprils. 


308 


MARS   AND   ITS   CANALS 


CIIAl'.    XXIV 


IV.     May  4. 


As  the  planet  now  went  away  and  detail  should  have 
dimmed,  the  Brontes  proceeded  to  do  the  opposite.  One 
had  almost  said  it  was  actuated  by  a  spirit  of  con- 
trariety. For  now  when  it 
had  reason  to  grow  faint 
it  grew  in  conspicuous- 
ness;  just  as,  before,  when 
it  should  have  become  evi- 
dent, it  had  declined.  Dis- 
tinctly farther  off  and 
smaller  as  the  planet  was 
at  the  next  presentation, 
the  Brontes  had  clearly 
developed  both  in  tone  and  in  the  amount  of  it  visible. 
This  was  in  May  (Drawings  IV  and  V).  In  June  bad 
seeing  prevented  good  ob- 
servations, but  in  July, 
Drawing  VI,  when  the  re- 
gion again  came  round,  the 
Brontes,  in  spite  of  the  then 
greatly  increased  distance, 
asserted  itself  so  strongly 
that  even  in  not  very  good 
seeing  its  presence  could 
not  be  passed  by. 

This  contrariety  of  behavior  had  about  it  one  very 
telling  feature.    That  the  canal  waxed  or  waned  in  exact 


CHAP.   XXIV 


CANAL   DEVELOPMENT 


309 


opposition  to  distance  and  even  toward  the  last  to  see- 
ing too,  showed  conclusively  that  neither  distance  nor 
definition  could  in  any  way  be  held  responsible  for  its 
metamorphoses.  A  very  fortunate  circumstance,  this  of 
the  observations,  for  it  directly  eliminated  size  of  disk, 
phase,  and  seeing,  for  which  correction  are  none  too  easy 
to  make,  and  which  in  the  minds  of  the  sceptical  could 
always  remain  as  unex- 
plained possibilities  of  error. 
The  mean-canal  car- 
touches show  synthetically, 
and  all  the  more  conclu- 
sively for  being  composite, 
the  laws  of  the  flux  of  the 
canals.  Something  more  of 
vividness,  however,  is  im- 
parted by  the  actual  look  of 
one  of  the  constituents  during  the  process.  It  is  the 
difference  between  seeing  a  composite  picture  made 
from  a  given  group  of  men  and  the  gazing  on  the  actual 
features  of  any  one  of  them.  So  much  is  gained  by  the 
drawings  across  the  page  of  the  Brontes  at  different 
stages  of  its  evolution  during  the  period  here  concerned. 
But  in  another  way,  too,  the  one  canal  may  be  made  to 
yield  a  more  lifelike  representation  of  the  process  than 
a  number  taken  together  are  capable  of  affording.  In 
the  mean-canal  cartouches  each  canal  is  treated  as  an 


VI.    July  18. 


310  MARS   AND   ITS   CAXALS  CHAP,  xxiv 

entity;  but  it  is  possible  to  consider  a  canal  by  parts, 
and  by  so  doing  to  see  it  in  action,  as  it  were.  It 
occurred  to  me  to  treat  the  Brontes  in  this  way.  For 
this  purpose  I  divided  the  canal  into  sections,  five  of 
them  in  all,  between  the  point  where  it  left  the  Pro- 
pontis,  at  a  spot  called  the  Propropontis,  to  where  it 
ended  in  the  Sinus  Titanum.  The  first,  the  most 
northern,  extended  as  far  as  Semnon  Lucus,  the  south- 
ernmost outpost  of  the  Propontis  congeries  of  spots. 
The  second  continued  on  from  these  to  Eleon,  the 
junction  where  the  Erebus  crossed.  The  third  thence 
to  Utopia,  where  the  canal  met  the  Orcus;  the  fourth 
to  an  arbitrary  point  in  latitude  8°  south,  and  the  fifth 
and  last  to  the  Sinus  Titanum.  The  lengths  of  these 
sections  were  respectively :  12°,  16°,  15°,  12°,  and  13°. 
Each  of  the  sections  was  then  treated  as  if  it  were  a 
separate  canal  and  its  cartouche  found.  To  the  car- 
touches' determination  there  were  available  drawings: 

January  21-25       .....  12  drawings. 

February  23-March  2    .         .         .         .  15  drawings. 

March  28-April  5           .         .         .         .  14  drawings. 

April  26-May  8 27  drawings. 

June  3-16 6  drawings. 

July  11-21 16  drawings. 


90  drawings  in  all. 

The   cartouches   are   given   in   the   plate   opposite, 
which  is  constructed  precisely  like  the  one  for  the  mean 


CHAP.    XXIV 


CANAL   DEVELOPMENT 


311 


canal  cartouches  presented  on  page  298.  The  mid-lati- 
tude of  the  section  and  its  mid-longitude  are  given  in 
the  margin  with  its  description. 

Examining  them  now  we  note  a  family  resemblance 
between  the  successive  cartouches.     All  sink  slowly 


-BRONTES 

~     showing  Successive  Development  South 
January  to  July,igoj 


on  the  left  to  rise  sharply  from  their  lowest  point  to  the 
right.  Such  resemblance  betokens  the  action  of  one 
and  the  same  cause. 

Next,  although  the  curves  are  resemblant,  each  has 
been,  as  it  were,  sheered  to  the  right  as  one  reads  down ; 
that  is,  the  action  took  place  later  and  later  as  the 
latitude  was  north. 

Lastly,  the  dying  out  of  a  previous  impulse  can  be 


312  MAES   AND  ITS   CANALS  CHAP,  xxiv 

traced  in  the  cartouches,  which  shows  that  the  canals 
were  quickened  six  months  previously  from  the  south 
polar  cap,  as  they  were  now  being  quickened  from  the 
north  polar  one. 


CHAPTER  XXV 

HIBERNATION   OF   THE    CANALS 

/CONNECTED  with  the  conduct  of  the  canals  is  a 
phenomenon,  examples  of  which  were  early  noted 
in  a  general  way  by  Schiaparelli  and  later,  but  of 
which  the  full  import  and  exhibition  only  came  to  light 
during  the  opposition  of  1903  by  a  very  striking  meta- 
morphosis: what  may  be  called  the  hibernation  of  a 
canal  for  a  longer  or  shorter  term  of  years.  What 
observation  discloses  is  certainly  curious.  For  several 
successive  oppositions  a  canal  will  be  seen  in  a  definite 
locality,  as  regular  in  seasonal  recurrence  as  it  is  per- 
manent in  place,  a  well-recognized  feature  of  the  disk. 
Then  to  one's  surprise,  with  the  next  return  of  the 
planet,  it  will  fail  to  appear,  and  will  proceed  to  remain 
obliterate  without  assignable  cause  for  many  Martian 
years,  until  as  unexpectedly  it  will  be  found  what  and 
where  it  was  before.  Neither  to  deposition  of  hoar- 
frost, such  as  frequently  whitens  whole  regions  of  Mars, 
nor  to  other  circumstances  can  be  attributed  its  dis- 
appearance. Without  apparent  reason  it  simply  ceases 
to  be  and  then  as  simply  comes  back  again. 

313 


314  MAES  AND  ITS  CANALS  CHAP,  xxv 

Such  bopeep  behavior  is  quite  beyond  and  apart 
from  the  seasonal  change  in  visibility,  to  which  all  the 
canals  are  by  their  nature  subject.  For  being  creatures 
of  the  semi-annual  unlocking  of  the  water  congealed 
about  the  polar  caps,  they  quicken  into  growth  and 
visibility,  each  in  its  season,  and  as  regularly  die  out 
again.  Different,  however,  is  the  phenomenon  to 
which  I  now  refer.  In  it  not  a  seasonal  but  a  secular 
change  is  concerned.  The  season  proper  to  the  canal's 
increase  will  recur  in  due  course,  and  the  canals  round 
about  it  will  start  to  life,  yet  the  canal  remains  unquick- 
ened.  Nothing  responds  where  in  years  the  response 
was  immediate  and  invariable.  The  canal  lies  dormant 
spite  of  seasonal  solicitation  to  stir. 

Such  curious  hibernation  was  early  hinted  to  the 
keenness  of  Schiaparelli,  and  most  incomprehensible  as 
well  as  difficult  of  verification  at  that  stage  the  phe- 
nomenon was.  That  the  absence  was  a  fact,  however, 
he  assured  himself,  although  he  was  not  able  to  prove 
an  alibi.  But  at  the  last  opposition  an  event  of  the 
sort  occurred  which,  from  the  length  of  time  the  planet 
was  kept  under  observation,  combined  with  continued 
suitableness  of  the  seeing,  unmasked  the  process.  In 
the  light  of  what  then  happened,  taken  in  connection 
with  the  side-lights  thrown  upon  it  by  the  canal's  past 
and  by  the  knowledge  we  have  meanwhile  gained  of  the 
planet's  physical  condition,  the  riddle  of  the  phenome- 


CHAP,  xxv     HIBERNATION   OF   THE   CANALS  315 

non  may  in  part  at  least  be  read,  and  most  interesting 
and  instructive  the  reading  proves  to  be. 

Among  the  initial  canals  detected  by  Schiaparelli, 
in  1877,  was  a  tricrural  set  of  lines  recalling  the  heraldic 
design  of  three  flexed  legs  joined  equiangularly  above 
the  knees.  It  lay  to  the  east  of  the  Syrtis  Major,  and 
he  called  its  three  members  the  Thoth,  the  Triton,  and 
the  Nepenthes.  Starting  from  the  head  of  his  gulf 
of  Alcyonius,  at  a  point  now  known  to  be  occupied  by 
the  oasis  called  Aquae  Calidae,  the  Thoth  started 
south  inclining  westward  as  it  went,  till  in  longitude 
267°  and  latitude  15°  north,  it  met  the  Triton,  which 
had  come  from  the  Syrtis  Minor  with  similar  westward 
inclination.  To  the  same  point  in  the  same  manner 
came  the  Nepenthes.  Part  way  along  the  course  of  the 
latter  was  to  be  seen  a  small  dark  spot,  the  Lucus 
Moeris,  which  he  estimated  at  four  degrees  in  diameter. 
Some  of  the  markings  were  easier  than  others,  the 
easiest  of  all  being  the  Lucus  Tritonis,  a  largish  dark 
spot  at  the  common  intersection  of  all  three  canals; 
but  that  none  of  the  markings  were  remarkably  diffi- 
cult is  sufficiently  shown  by  their  detection  at  this  early 
stage  of  Schiaparelli's  observations.  It  is  worth  noting 
also  that  he  discovered  the  southern  ones  first;  the 
Thoth  not  being  seen  till  March,  1878.  As  his  then 
recognition  of  these  canals  witnesses,  they  must  have 
been  among  the  most  evident  on  the  disk.  And  the 


316  MARS   AND  ITS   CANALS  CHAP,  xxv 

point  is  emphasized  by  the  fact  that  he  failed  at  this 
opposition  to  detect  the  Phison  and  the  Euphrates 
as  separate  markings. 

Much  the  same  the  three  canals  appeared  to  him  at 
the  next  opposition  of  1879,  the  Thoth  being  seen  at  its 
several  presentations  from  October  5,  1879,  to  January 
11,  1880. 

At  the  next  opposition  a  noteworthy  alteration 
occurred,  the  full  significance  of  which  escaped  recog- 
nition. Schiaparelli  saw,  at  the  place  where  the  Thoth 
had  been,  two  lines  which  he  took  for  a  gemination  of 
that  canal,  one  of  which  followed  the  course  of  the  old 
Thoth,  while  the  other  went  straight  from  the  Sinus 
Alcyonius  to  the  Little  Syrtis,  or,  more  precisely,  to  the 
junction  of  the  Triton  and  the  Lethes.  It  was  not  the 
Thoth,  however,  but  something  unsuspected,  of  more 
importance. 

In  1884  the  Thoth  showed  really  double,  the  western 
line  being  much  the  stronger,  "una  delle  piu  grosse 
linee  que  si  vedessero  sul  disco."  That  neither  branch 
went  farther  than  the  meeting-place  with  the  Nepen- 
thes argues  that  it  was  indeed  the  Thoth  that  was  seen. 
Schiaparelli  himself  had  no  doubt  on  the  subject,  al- 
though he  drew  the  double  canal  he  saw  due  north  and 
south  from  the  tip  of  the  Sinus  Alcyonius  to  the  junc- 
tion, but  nevertheless  along  the  263°  meridian. 

In  1886  and  1888  the  system  was  in  all  essentials, 


CHAP,  xxv    HIBERNATION   OF  THE   CANALS  317 

what  it  had  been  in  1877  and  1879,  except  that  the 
Thoth  and  Nepenthes  were  double  and  were  more 
minutely  seen. 

Here,  then,  was  a  system  of  canals  and  spots  which 
for  six  Martian  years  had  been  a  persistent  and  sub- 
stantially invariable  feature  of  the  Martian  surface. 
Any  changes  in  it  had  been  of  a  secondary  order  of  im- 
portance, while  its  general  visibility  was  of  the  first. 
It  is  possible,  then,  to  judge  of  my  perplexity  when  in 
beginning  my  observations  in  1894  no  sign  of  the  system 
could  I  detect.  Of  neither  the  Thoth,  the  Triton,  the 
Nepenthes,  nor  the  Lucus  Moeris  was  there  trace.  And 
yet,  from  the  other  canals  visible,  it  was  evident  that 
the  disk  was  quite  as  well  seen  as  it  had  been  by  Schia- 
parelli.  Not  only  were  practically  all  his  canals  there, 
but  many  much  smaller  ones  were  to  be  made  out. 
And  the  same  was  true  of  the  spots,  a  host  of  such  not 
figured  by  him  appearing  here  and  there  over  the 
planet's  surface. 

Nor  was  this  all.  Instead  of  the  Thoth,  another  canal 
showed  straight  down  the  disk  from  the  Syrtis  Minor 
to  the  Aquae  Calidae.  This  canal  was  as  unmistakable 
as  the  Thoth  had  been  before  to  Schiaparelli.  It  was 
among  the  first  to  be  detected,  and  continued  no  less 
conspicuous  to  the  end,  the  dates  at  which  it  was  seen 
being  July  10,  August  14,  and  October  21.  I  called  it 
the  Amenthes,  identifying  it  with  the  canal  so  named 


318  MARS  AND   ITS   CANALS  CHAP,  xxv 

in  Schiaparelli's  chart  published  in  Himmel  und 
Erde,  of  the  ensemble  of  his  observations  from  1877  to 
1888.  But  in  his  Memoirs  he  never  called  it  so,  seeing 
it,  indeed,  only  in  1881-1882,  and  deeming  it  then  the 
Thoth.  Nevertheless,  in  1894,  it  was  the  conspicuous 
canal  of  the  region,  and,  what  is  more,  had  come,  as 
it  proved,  to  stay. 

The  invisibility  of  the  Thoth  continued  for  me  the 
same  during  the  succeeding  oppositions  of  1896-1897 
and  1901.  At  the  former  opposition  I  drew  it  in  1896 
on  July  28,  August  26,  September  2,  October  5-9, 
seeing  it  single ;  and  in  1897  on  January  12-19,  Febru- 
ary 21,  and  March  1.  It  was  single  but  with  suspicions 
of  doubling  in  January,  and  was  indubitably  double  in 
February.  As  for  the  Thoth,  I  had  come  to  consider 
it  and  the  Amenthes  one,  attributing  their  diversity 
of  depiction  to  errors  in  drawing.  For  while  the  Thoth 
remained  obstinately  invisible,  the  Amenthes  presented 
itself  as  substitute  so  insistently  as  to  make  one  of  the 
most  obvious  canals  upon  the  disk. 

One  exception  only  was  there  to  this  state  of  things. 
On  June  16,  1901,  my  notes  contain  this  adumbration 
of  a  something  else:  "Amenthes  sometimes  appeared 
with  a  turn  to  it  two-thirds  way  up;  two  canals  con- 
cave to  the  Syrtis  Major." 

So  matters  opened  at  the  opposition  of  1903.  With 
the  advent  of  the  planet  and  the  presentation  in  due 


CHAP,  xxv    HIBERNATION   OF  THE   CANALS 


319 


Amenthes  alone  in  February. 


course  of  Libya  in  February,  the  Amenthes  duly  ap- 
peared, much  as  it  had  showed  at  the  opposition  before, 
only  less  salient.  It  was  a 
confused  and  seemingly  nar- 
rower double.  Suspected 
on  the  16th  of  that  month, 
it  was  definitely  seen  from 
the  18th  to  the  23d.  Of 
the  Thoth  no  mention  is 
made  either  in  the  notes  or 
in  the  drawings.  When  the 
region  came  round  again,  in 

March,  the  Amenthes  was  still  there,  showing  more 
feebly,  however,  than  it  had  in  February,  in  spite  of 
better  seeing  and  the  fact 
that  the  planet  had  consid- 
erably neared.  Clearly  the 
canal  was  fading  out ;  a  fact 
further  witnessed  to  by  the 
following  note  made  on 
March  25:  "  Throughout 
this  opposition  thus  far  the 
dark  triangle  tipped  by 
Aquae  Calidae  has  been 
sharply  divided  in  intensity  from  the  Amenthes,  which 
is  very  narrow  and  exceedingly  faint."  Still  was 
there  no  trace  of  the  Thoth. 


Amenthes  feebler  and  still  alone 
in  March. 


320 


MAES   AND   ITS   CANALS 


CHAP.   XXV 


With  the  April  presentation  entered  a  new  order  of 
things.  When  the  region  first  became  visible,  on  the 
16th,  the  Amenthes  could  still  be  seen  and  alone; 
but  on  the  19th,  as  the  relative  falling  back  of  the  Mar- 
tian longitudes  swung  the 
region  nearer  the  centre  of 
the  disk,  the  Thoth  appeared 
alongside  of  it.  On  the 
20th  the  Thoth  showed 
alone.  Unmistakable  it  was 
and  just  as  Schiaparelli  had 
drawn  it,  accompanied  by 
the  Triton  and  the  curved 
Nepenthes.  The  thing  was 
a  revelation.  What  before  I 
had  seen  only  in  the  spirit  of  another's  drawings  stood 
there  patent  to  me  in  the  body  of  my  own ;  while  the 
Amenthes,  to  which  I  had  so  long  been  accustomed, 
had  vanished  into  thin  air.  Only  a  trace  of  it  was 
now  and  then  to  be  made  out.  So  startlingly  strange 
was  the  metamorphosis  that  I  could  not  at  first  trust 
my  eyes,  and  questioned  the  broken  line,  which  had 
replaced  the  straight,  for  some  ocular  deception.  But 
nothing  I  could  do  would  rectify  it.  The  Amenthes 
was  gone  and  the  Thoth  stood  in  its  stead. 

At  the  next  presentation,  May  26  to  June  8,  the 
phenomena  were  repeated,  and  with  increasing  clarity. 


Appearance  of  Thoth  with  Tri- 
ton and  curved  Nepenthes. 
Amenthes  vanished.  April  20. 


CHAP,  xxv     HIBERNATION   OF   THE   CANALS 


321 


And  then  of  a  sudden,  on  May  29,  I  saw  the  long- 
given-up  Lucus  Moeris.  There  it  was  indubitably. 
And  its  definiteness  was  the  most  astonishing  part  of 
the  affair.  It  was  no  question  of  difficult  detection. 
Indeed,  I  had  not  been  on  the  lookout  for  it,  having 
searched  the  region  too  often 
fruitlessly  before  to  have 
left  incentive  to  search  again. 
And  so,  when  I  was  not 
searching,  the  thing  of  its 
own  accord  stepped  forth 
to  sight.  It  was  a  small 
round  dot,  like  to  any  other 
oasis,  and  showed,  as  it  were, 
a  black  pearl  pendent  by 
the  Nepenthes  from  the  Syrtis's  ear.  For  the  Libyan 
bay  made  a  dark  projection  of  the  sort  high  up  on  the 
Syrtis's  eastern  side,  from  which  the  Nepenthes,  pre- 
cisely as  Schiaparelli  had  drawn  it,  curved  down  to  the 
point  where  the  Thoth  and  Triton  met.  All  three 
canals  were  geminated,  the  gemination  being  about 
three  degrees  wide. 

And  now  occurred  the  last  act  in  the  drama.  In 
July  the  Amenthes  reappeared,  showing  alongside  of 
the  Thoth-Nepenthes,  and  thus  removing  any  possible 
doubt  as  to  their  separate  identity.  It  had,  indeed, 
become  the  stronger  of  the  two,  having  gained  in 


Advent  of  the  Lucus  Moeris. 
May  29. 


322 


MARS    AND   ITS   CANALS 


strength  in  the  interval  between  June  and  July  and 
the  Thoth-Nepenthes  having  lost.  The  lines  were  in 
process  of  relapsing  into  the  status  quo  ante.  Had 
these  three  presentations  not  been  watched,  the  brief 
apparition  of  the  Thoth-Nepenthes  had  been  missed 
and  with  it  the  revealing  of 
its  curious  character,  and 
of  certain  deductions  there- 
upon. 

First  among  these  is  a 
truth  of  which  I  have  long 
been  convinced ;  to  wit,  that 
when  a  seeming  discordance 
arises  between  the  portrayals 
of  a  canal,  it  is  commonly 
not  a  case  of  mistake  nor  of  change,  but  one  of  separate 
identity.  The  canal  has  not  shifted  its  place,  nor  has 
an  error  been  committed;  the  fact  is  that  one  canal 
has  been  observed  at  one  time,  another  at  another. 

So  it  was  here,  and  thus  were  the  old  and  the  new 
observations  reconciled.  There  had  been  no  mistake 
in  either.  Two  separate  canals  accounted  for  the  dis- 
crepancy, and  only  an  unfounded  distrust  of  the  accu- 
racy possible  in  such  observations  was  to  blame  for 
any  failure  to  recognize  the  fact. 

Now,  scrutiny  of  the  notes  upon  the  appearance  of  the 
two  canals,  together  with  their  labeling  by  the  seasonal 


Amenthes  with  Thoth-Nepenthes. 
July. 


CHAP,  xxv     HIBERNATION   OF   THE   CANALS 


323 


longitudes  of  the  planet  at  the  dates  they  were  made, 
discloses  a  curious  relation  between  the  two.  The 
seasonal  longitudes  are  important,  as  they  date  the 
phenomena  according  to  the  Martian  calendar.  Or- 
dered thus,  the  successive  aspects  reveal  first  a  seasonal 
change  in  each  canal  and  then  over  and  above  this  a 


CARTOVCHES 

ures  OF  VISIBILITY 

.  THOTH    jr,d  THE.IK  COMBINATION. 


secular  one.  And  this  secular  change  was  such  as  to 
cause  the  two  canals  to  alternate  in  visibility.  When 
the  one  was  present  the  other  was  not,  and  vice 
versa. 

We  shall  see  this  more  clearly  and  at  the  same  time 
bring  out  a  curious  relation  between  the  two  systems, 
the  broken  bow  of  the  Thoth-Nepenthes-Triton  and  the 
straight  arrow  of  the  Amenthes,  while  looking  at  the 


324  MAKS  AND  ITS   CANALS  CHAP,  xxv 

cartouches  of  the  Thoth,  the  Amenthes,  and  a  combi- 
nation of  both  given  in  the  plate  on  previous  page. 

The  antithetical  character  of  the  two  canals  is  appar- 
ent. But  what  is  further  interesting,  the  combination 
cartouche  of  both  bears  a  singular  resemblance  to  that 
of  the  mean  canal  of  the  north  tropic  zone,  the  zone 
to  which  both  canals  belong.  Here,  then,  is  a  combi- 
nation which  is  perfectly  regular  while  each  of  its  con- 
stituents is  anomalous. 

And  now  we  come  to  something  as  important:  at 
the  opposition  of  1905  the  curious  alternation  meta- 
morphosis was  enacted  anew.  The  Amenthes  appeared, 
disappeared  to  be  replaced  by  the  Thoth,  and  then  re- 
appeared again  beside  the  other.  This  corroboration 
of  behavior  showed  the  previous  observations  to  have 
been  due  to  no  mistake,  and  only  served  to  deepen  the 
interest  in  this  last  and  more  singular  phase  of  canal 
conduct. 


CHAPTER  XXVI 

ARCTIC   CANALS   AND   POLAR   RIFTS 

T  AST  in  time  but  not  least  in  importance  of  the 
details  of  canal  development  to  be  detected  is  one 
that  connects  these  strange  features  directly  with  the 
melting  of  the  polar  caps.  The  cartouches  showed 
that  such  connection  was  to  be  inferred ;  the  facts  now 
to  be  recorded  depict  it  by  an  identity  of  place  between 
certain  phenomena  of  the  two  subjects  following  one 
another  in  order  of  time. 

On  January  8,  1897,  while  scanning  the  planet,  I 
was  suddenly  ware  of  a  rift  in  the  north  polar  cap.  It 
ran  a  little  to  the  west  of  south  from  where  it  started 
in  at  the  cap's  edge  and  went  clean  through  to  the  limb, 
the  pole  being  then  slightly  tilted  away  from  us.  At  the 
time  it  seemed  to  be  the  first  rift  ever  seen  in  that 
cap ;  but  on  opening  a  little  later  Schiaparelli's  Memoria 
Quarta,  which  had  just  arrived,  the  first  thing  my  eye 
fell  on  was  a  drawing  of  a  rift  in  the  north  polar  cap 
observed  by  him  when  the  planet  had  held  the  like 
attitude  toward  the  Earth  thirteen  years  before.  Ref- 
erence to  its  longitude  showed  it  to  be  the  identical 

325 


326  MARS  AND  ITS   CANALS  CHAP,  xxvi 

rift,  seen  again  after  all  these  years  and  the  only  one 
so  far  seen  in  the  northern  cap. 

At  the  next  opposition  more  rifts  were  detected,  one 
in  especial  on  December  27,  running  from  Arethusa 
Lucus,  then  upon  the  edge  of  the  cap,  athwart  the 
snow  in  a  northwesterly  direction. 

In  the  forepart  of  the  opposition  of  1901,  which  in  its 
Martian  season  corresponded  to  that  in  1897,  when  the 
rift  had  been  observed,  many  rifts  were  detected  in  the 
cap,  and  among  them  one  traversing  the  cap  north- 
northeasterly  in  longitude  136°. 

So  far  the  season  when  the  cap  had  been  observed 
was  that  when  the  rifts  were  in  process  of  forming. 
The  ground  they  and  the  snow-cap  covered  had  not  yet 
at  any  opposition  been  uncovered. 

It  was  only  when  my  observations  began  in  the 
latter  half  of  the  opposition  of  1901  that,  the  season  on 
Mars  having  so  far  advanced,  all  snow  in  those  latitudes 
had  melted.  Then  appeared,  however,  the  canal 
Hippalus,  an  arctic  canal  of  some  importance,  lying 
on  that  part  of  the  planet  previously  occupied  by  the 
polar  cap.  When  later  studying  the  observations 
on  the  rifts  I  remembered  this  canal,  and  turning 
to  the  drawing  made  some  months  before  to  compare 
the  two  critically,  discovered  that  the  canal  occupied 
the  precise  position  held  earlier  by  the  rift.  One  had 
said  the  rift  had  never  vanished,  but  that  the  white 


CHAP.  XXVI 


CANALS   AND  KIFTS 


327 


surrounding  it  had  simply  turned  to  ochre.  Here, 
then,  was  a  striking  coincidence  of  place,  too  exact  to 
be  the  result  of  chance. 

Impressed  by  the  identity,  I  examined  all  the  other 
rifts  seen  early  in  1901,  comparing  them  with  the  arctic 
canals  seen  later,  to  the  finding  of  no  less  than  five  cases 
of  the  same  coinciding  positions. 

The  importance  of  the  identification  here  made  of  an 
arctic  canal  with  a  previous  rift  in  the  polar  cap  has 
led  me  to  make  a  list  of  the  canals  thus  identified  at 
this  opposition. 


VISIBLE  AS  A  RIFT 

VISIBLE  AS  A  CANAL 

Hypanis 

Hippalus 
Rhombites 
Python 
Zygatis 

January  1  and  February  4 

January  19  and  February  4 
February  4 
February  20 
January  18,  19 

April  18  (?),  May  20,22, 
27,  June  4,  5,  6,  7,  8,  25 
April  18,  May  27 
May  27 
March  31 
May  7,  June  3  to  8 

If  it  be  asked  why  these  canals  do  not  appear  recorded 
at  the  March  presentation  as  either  the  one  phenomenon 
or  the  other,  the  answer  is  twofold.  First,  because  they 
showed  as  shadings  lost  amidst  a  shaded  mass;  and, 
secondly,  the  observations  at  several  oppositions  indi- 
cate a  great  amount  of  haze  over  the  region  at  that 
season  of  the  Martian  year. 

We  may  now  go  back  to  the  very  first  rift,  that  of 
1897.  The  Martian  season  grew  later  with  each  sue- 


328  MARS   AND  ITS   CANALS  CHAP,  xxvi 

ceeding  opposition,  and  it  so  chanced,  abetted  by  this 
fact,  that  the  delaying  snow  was  never  seen  covering 
that  part  of  the  planet  again  and  so,  of  course,  not 
the  rift.  The  Martian  summer  in  those  high  lati- 
tudes came  on,  and  with  it  brought  the  great  arctic 
canal,  the  Jaxartes,  into  conspicuousness.  The  canal 
in  consequence  had  been  observed  for  some  time 
before  it  proclaimed  itself  the  apotheosis  of  a  rift 
and  that  of  the  first  and  most  important  rift  of  all. 
Comparison  of  position,  however,  entirely  confirmed 
the  conjecture  and  added  another  and  the  most 
striking  of  all  to  the  list. 

These  six  canals,  on  the  whole  the  largest  which  run 
into  the  northern  cap,  have  thus  a  dual  character. 
Starting  originally  as  rifts,  they  later  come  out  un- 
mistakably as  canals.  So  that  we  may  say  in  general 
that  the  two  phenomena  are  different  seasonal  states 
of  the  same  thing.  This  instantly  explains  the  rifts, 
the  origin  of  which  we  found  of  so  difficult,  not  to  say 
impossible,  interpretation  before  in  these  pages,  and 
incidentally  it  confirms  what  we  deduced  on  other 
grounds  as  the  character  of  the  canals;  to  wit,  strips 
of  vegetation.  For  if  the  cap-  covered  desert  and 
fertility  alike,  it  is  precisely  over  the  latter  that  it 
would  first  melt. 

Vegetation  has  the  property  of  melting  snow.  The 
metabolism  of  the  plant,  like  that  of  the  animal,  though 


CHAP,  xxvj  CANALS   AND  RIFTS  329 

in  a  less  degree,  generates  caloric.  A  living  animal  is 
warm,  even  the  so-called  cold-blooded  ones,  in  some 
sort,  and  a  growing  plant  is  too.  The  chemic  processes 
concerned  give  off  heat,  though  in  such  small  quantities 
that  we  are  often  not  aware  of  it.  While  the  plant  lies 
dormant  it  stays  cold,  but  the  moment  its  sap  begins 
to  run  under  the  rays  of  the  spring  sun  it  rises  in 
temperature  above  its  winter  surroundings.  All  it 
needs  to  this  awakening  is  sun  and  water,  and  both  it 
gets  in  its  place  in  the  polar  cap  after  the  passing  of  the 
vernal  equinox.  The  time,  therefore,  is  suitable,  for 
it  is  not  till  after  that  equinox  is  passed  that  any  of  the 
above  phenomena  occur.  In  consequence  the  snow 
about  it  melts  and  the  plants  themselves  show  as 
dark  rifts  splitting  the  cap. 

This  quite  unexpected  identity  of  two  seemingly 
diverse  phenomena,  and  the  unsolicited  support  its 
only  explanation  lends  to  the  general  theory,  is  an 
instance  of  what  is  constantly  occurring  as  observa- 
tion of  the  planet  is  pushed  farther  and  farther.  Facts 
every  little  while  arise  which  prove  to  fit  into  place  in 
the  scheme  when  neither  the  facts  nor  their  fitness 
could  have  been  foreseen. 


CHAPTER  XXVII 

OASES;  KINEMATIC 

O  UB JECT  to  change  also  are  the  oases ;  and  in  the 
same  manner  apparently  as  the  canals.  They 
grow  less  evident  at  a  like  season  of  the  Martian  year. 
They  do  this  seemingly  by  decreasing  in  size.  Whereas 
in  the  full  expanse  of  their  maturity  they  show  as 
round  spots  of  appreciable  diameter,  as  the  season 
wanes  they  contract  to  the  smallest  discernible  of  dots. 
All  but  the  kernel,  as  it  were,  fades  out,  and  even  this 
may  disappear  from  sight.  The  Phrenix  Lake  in 
its  summer  time  is  a  very  dark  circular  spot,  small 
indeed  yet  of  definite  extension ;  in  its  winter  it  shrinks 
to  a  pin  point,  and  is  often  not  visible  at  all.  Some- 
times the  husk  apparently  persists,  a  ghostlike  remi- 
niscence of  what  it  was,  with  the  kernel  showing  dark- 
pointed  in  its  centre.  Thus  the  Lucus  Lunae  appeared 
at  the  opposition  of  1905.  A  faint  wash  betokened  the 
presence  of  the  Lucus,  through  which  now  and  again 
a  black  pin-point  pierced. 

In  this  visible  decrease  of  size  we  get  a  revelation  as 
to  what  takes  place  impossible  in  the  case  of  the  canals, 

330 


CHAP,  xxvn  OASES ;   KINEMATIC  331 

the  tenuous  character  of  which  precludes  more  than 
inference  as  to  the  process. 

Like  the  canals,  latitude,  together  with  the  suitable 
season  of  the  planet's  year,  are  the  determining  factors 
in  their  development.  In  what  corresponded  to  our 
July  of  the  northern  hemisphere  the  oases  in  the 
sub-arctic  and  north  temperate  zones  were  conspicu- 
ous; black  spots  that  showed  in  profusion  along  the 
parallels  of  40°,  50°,  and  60°  north.  At  the  same 
time  the  equatorial  ones,  those  along  the  Eumenides- 
Orcus,  which  had  been  most  evident  in  1894,  hardly 
came  out.  It  had  been  their  time  then  as  it  was  that 
of  the  others  now.  The  law  of  development  is  not  so 
simple  as  on  the  earth,  depending,  like  that  of  the 
canals,  not  only  upon  the  return  of  the  sun,  but  upon 
the  advent  of  the  water  let  loose  from  about  the 
polar  caps.  Thus  the  equatorial  oases  are  subject  to 
two  seasonal  quickenings,  one  from  the  north,  the 
other  from  the  south. 

In  regard  to  their  method  of  evolution  or  devolution 
a  most  curious  observation  happened  to  me  in  1903. 
Usually  the  oases  are  of  solid  tone  throughout ;  equally 
sombre  from  centre  to  circumference.  But  in  this 
case  such  uniform  complexion  found  exception.  On 
March  1,  1903,  the  Ascraeus  Lucus  came  out  strangely 
differentiated,  a  dark  rim  inclosing  a  less  dark  kernel. 
The  sight  was  odd  enough  to  command  comment  in  the 


332  MAES  AND  ITS  CANALS          CHAP,  xxvn 

shape  of  a  sketch  which  accompanied  the  note,  and  the 
further  remark  that  other  spots  had  similarly  that  year 
affected  the  like  look.  That  the  effect  was  optical  did 
not  seem  to  me  the  case.  Other  spots  at  other  times 
showed  nothing  of  the  sort.  If  it  was  due  to  objective 
cause  it  gathers  circumstance  from  what  was  then  the 
Martian  time  of  year.  For  the  season  was  such  that 
the  spot  should  then  have  been  in  process  of  waning; 
and  the  effect  would  indicate  that  in  so  doing  the  tone 
of  the  centre  went  first,  that  of  the  circumference  fading 
last.  This  would  be  in  accordance  with  a  growth 
proceeding  outward  and  a  decay  that  followed  in  its 
steps. 

When  to  this  we  add  the  look  of  the  oases  at  the 
antithetic  season,  —  often  a  faint  shading  only,  with  or 
without  a  darker  pin-point  at  its  core,  —  we  are  led 
to  the  belief  that  the  area  of  the  oasis  is  unchangeable 
and  that  its  growth  means  a  deepening  of  tint. 

So  far,  then,  as  it  is  possible  to  particularize  them, 
the  oases  develop  from  a  small  nucleus,  perhaps  twenty 
miles  in  diameter,  perhaps  less,  and  from  this  spread 
radially  till  they  attain  a  width  of  seventy-five  or  one 
hundred  miles.  If  the  oasis  be  associated  with  a  double 
canal,  this  maximum  width  exactly  fits  the  space  be- 
tween the  twin  lines.  Even  when  no  double  enters 
the  oasis,  the  size  is  about  the  same.  This  size  attained, 
they  hold  it  for  some  months.  Then  they  proceed  to 


CHAP,  xxvn  OASES ;  KINEMATIC  333 

fade  out  to  their  initial  nucleus,  and  after  a  sufficient 
rest  the  process  starts  over  again. 

With  the  carets  something  of  the  same  sort  seems  to 
take  place  —  if  we  may  consider  as  betokening  a  gen- 
eral law  the  fact  that  in  1894  the  carets  at  the  mouths 
of  the  Phison  and  Euphrates  developed  before  their 
affiliated  canals.  But  about  them  much  less  is  yet 
known,  and  we  must  be  content  to  say  that  the  obser- 
vations of  1905  made  at  the  opposite  season  of  the 
canal's  year  seem  to  bear  this  out. 


PART   IY 

EXPLANATION 


CHAPTER  XXVIII 

CONSTITUTION   OF  THE   CANALS   AND  OASES 

A  S  rational  science  does  not  rest  content  with  raw 
results,  it  now  becomes  obligatory,  by  mar- 
shaling the  facts  to  suitable  discussion,  to  seek  to  find 
out  what  they  mean.  Now,  so  soon  as  we  scan  these 
phenomena  for  some  self-interpretation,  we  perceive 
one  characteristic  of  the  lines  which  at  once  appears 
to  direct  us  to  their  nature  and  justifies  itself  as  a  sign- 
post with  increasing  certainty  as  we  read  on.  This 
trait  is  the  very  simple  yet  most  significant  one  of 
showing  intrinsic  change :  the  lines  alter  in  visibility 
with  time.  This  primary  proclivity  we  do  not  even  need 
the  cartouches  to  establish.  That  the  lines  change  is 
palpable  to  any  one  who  will  watch  them  long  enough. 
Schiaparelli  was  struck  by  the  fact  early  in  his  study  of 
the  planet,  and  it  forces  itself  on  the  notice  of  any  care- 
ful observer  who  compares  his  own  observations  with 
one  another  at  intervals.  But  though  the  cartouches  are 
not  needed  to  a  first  revelation  of  mutability,  they  serve 
to  certify  and  precise  it  to  much  further  information  on 
the  subject.  For,  that  these  changes  are  not  extrinsic, 
that  is,  are  not  caused  by  varying  definition,  distance, 


338  MARS  AND  ITS  CANALS         CHAP,  xxvm 

or  illumination,  they  make  patent  even  to  those  who 
have  never  seen  the  things  themselves  by  disclosing 
respective  differences  of  behavior  in  lines  similarly 
circumstanced  optically.  The  change  is  therefore 
intrinsic,  and  the  question  arises  to  what  can  such  in- 
trinsic change  be  due. 

In  searching  for  cause,  attention  is  at  once  attracted 
by  another  series  of  transmutations  that  manifests 
itself  upon  the  disk,  in  the  orderly  melting  of  the  polar 
caps.  For  the  existence  of  the  two  sets  of  metamor- 
phoses suggests  the  possibility  of  a  connection  between 
them.  The  inference  is  strengthened  when  we  note 
that  not  only  are  both  periodic,  but  that  furthermore 
the  period  of  the  two  is  the  same.  Each  polar  cap 
runs  through  its  gamut  of  change  in  a  Martian  year; 
the  canals  also  complete  their  cycle  of  growth  and  decay 
in  a  Martian  twelvemonth.  The  only  difference  be- 
tween the  two  is  that  each  polar  cap  has  but  one  maxi- 
mum and  one  minimum  in  the  course  of  this  time, 
while  most  of  the  canals  have  two  of  each,  though  the 
maxima  are  not  alike  nor  the  minima  either. 

Not  only  is  the  period  of  the  two  series  of  changes  the 
same,  but  the  one  follows  the  other.  For  the  develop- 
ment of  the  canals  does  not  begin  till  the  melting  of  the 
polar  cap  is  well  under  way.  Now,  as  the  polar  cap 
disintegrates  it  gives  rise,  as  we  have  seen,  to  a  dark  belt 
of  blue-green  which  fringes  its  outer  edge  and  retreats 


CHAP,  xxvin      CONSTITUTION   OF  CANALS  339 

with  it  as  it  shrinks.  This  tells,  directly  or  indirectly, 
of  a  product  let  loose.  After  this  belt  has  been  formed 
the  canals  nearest  to  it  proceed  to  darken,  then  those  a 
little  farther  off  follow  suit,  and  so  the  wave  of  visibility 
rolls  in  regular  routine  down  the  disk.  Here,  then,  at 
the  outset  we  have  a  chronic  connection  between  the 
two  phenomena,  the  disintegration  of  the  cap  and  the 
integration  of  the  canals. 

Of  water  we  saw  that  the  caps  were  undoubtedly 
composed,  and  to  water,  then,  let  loose  by  the  melting 
of  the  cap,  we  may  inferably  ascribe  the  thaumaturgy 
in  the  development  of  the  canals.  But  it  is  not  neces- 
sary to  suppose  that  this  is  done  directly.  That  the 
increased  visibility  of  the  canals  can  be  due  to  a  bodily 
transference  of  water  seems  doubtful,  if  for  no  other 
reason  than  the  delay  in  the  action.  Considerable 
time  intervenes  between  the  disappearance  of  the 
cap  and  the  appearance  of  the  canals,  except  in  the 
case  of  such  as  have  been  covered  by  it.  Transforma- 
tion consequent  upon  transference,  however,  would 
account  for  hesitancy.  A  quickening  to  vegetal 
growth  would  produce  the  counterpart  of  what  we 
see.  If,  set  free  from  the  winter  locking  up,  the  water 
accumulated  in  the  cap  then  percolated  equatorward, 
starting  vegetation  in  its  course,  this  would  cause 
the  increased  visibility  of  the  canals  and  at  the  same 
time  explain  the  seeming  delay,  by  allowing  for  the 


340  MAKS   AND  ITS  CANALS          CHAP,  xxvm 

time  necessary  for  this  vegetation  to  sprout.  This 
is  certainly  the  most  satisfactory  explanation  of  the 
phenomena. 

Thus  started,  the  vegetal  quickening  would  pass 
down  the  planet's  surface  and  give  rise  to  what  we  mark 
as  seasonal  change.  But,  though  in  one  sense  of  sea- 
sonal character,  a  little  consideration  will  show  that 
it  would  be  quite  unlike  the  seasonal  change  which  we 
know  on  earth. 

Could  we  see  our  earth  from  some  standpoint  in 
space,  we  should  mark,  with  the  advent  of  spring,  a 
wave  of  verdure  sweep  over  its  face.  If  freedom  from 
cloud  permitted  of  an  unimpeded  view,  this  flush  of 
waking  from  winter's  sleep  would  be  quite  evident  and 
could  be  seen  to  spread.  Starting  from  the  equator  so 
soon  as  the  sun  turned  north,  it,  too,  would  travel  north- 
ward, and,  distancing  the  sun,  arrive  by  midsummer 
well  into  the  arctic  zone.  Here,  then,  we  should  note, 
much  as  we  note  it  on  Mars,  a  tint  of  blue-green  super- 
pose itself  successively  upon  the  ochre  ground;  but 
the  mundane  and  the  Martian  vegetal  awakening 
would  differ  in  one  fundamental  respect;  the  earthly 
wave  would  be  seen  to  travel  from  equator  to  pole, 
while  the  Arian  travels  from  pole  to  equator.  Though 
clearly  seasonal  in  character,  both  of  them,  the  trans- 
formations would  be  opposite  in  action.  Some  other 
cause,  then,  must  be  at  work  from  what  we  are  familiar 


CHAP,  xxvin       CONSTITUTION   OF  CANALS  341 

with  on  earth.  This  other  cause  is  the  presence  or 
absence  of  moisture. 

Two  factors  are  necessary  to  the  begetting  of  vegetal 
life,  the  raw  material  and  the  reacting  agent.  Oxygen, 
nitrogen,  water,  and  a  few  salts  make  up  the  first  de- 
sideratum, the  sun  supplies  the  second.  Unless  both 
be  present,  the  quickening  to  life  never  comes.  Now, 
the  one  may  be  there  and  the  other  not,  or  the  other 
there  and  the  one  not.  On  earth  the  material  includ- 
ing water  is,  except  in  certain  destitute  localities, 
always  present;  the  sun  it  is  that  periodically  with- 
draws. Observant  upon  the  return  of  the  sun  is  there- 
fore the  annual  recurrence  of  vegetal  growth. 

On  Mars,  on  the  contrary,  water  is  lacking.  This 
we  now  know  conclusively  from  other  phenomena  the 
disk  presents  which  have  no  connection  with  the  present 
investigation  and  are,  therefore,  unprejudiced  witnesses 
to  the  fact.  No  permanent  bodies  of  water  stud  its  sur- 
face. That  the  so-called  seas  are  traversed  by  dark 
lines  permanent  in  place  is  one  of  several  proofs  of  this. 
The  only  surface  water  the  planet  knows  comes  from 
the  melting  of  its  polar  caps.  Vegetation  cannot  start 
until  this  water  reaches  it.  Consequently,  though  the 
sun  be  ready,  vegetation  must  wait  upon  the  coming 
of  the  water,  and  starting  from  near  the  pole  follow 
the  frugal  flood  equatorward. 

Now,  such  contrariety  of  progression  to  what  we 


342 


MARS   AND   ITS  CANALS 


CHAP.  XXVIII 


should  observe  in  the  case  of  the  earth  could  we  view 
it  from  afar  is  exactly  what  the  curves  of  visibility  of 


I-    ISC'    100     140°   SW 

PHENOLOCY  CURVES  -EARTH. 

A  -  Dead  Point  Of  Vegetation. 

(From  paper  in  Proc.  Amer.  Phil.  Soc.,  by  Percival  Lowell.) 

the  canals  exhibit.  Timed  primarily,  not  to  the  re- 
turn of  the  sun  but  to  the  advent  of  the  water,  vegetal 
quickening  there  follows,  not  the  former  up  the  lati- 
tudes but  the  latter  down  the  disk.  For  better  under- 


CHAP,  xxvin       CONSTITUTION   OF  CANALS 


343 


standing,  the  two  curves  of  phenological  quickening, 
the  mundane  and  the  Martian,  are  shown  in  the  dia- 


H/7NO 


(From  paper  in  Proc.  Amer.  Phil.  Soc.,  by  Percival  Lowell.) 

grams.  The  plates  represent  the  surfaces  of  the  two 
planets,  that  of  the  earth  being  shown  upside  down  with 
south  at  the  top  so  as  to  agree  with  the  telescopic  de- 
piction of  the  topography  of  Mars.  The  stars  mark  the 


344  MAES  AND  ITS  CANALS         CHAP,  xxvm 

epoch  of  the  dead-point  of  vegetation  at  successive 
latitudes;  the  time  increasing  toward  the  right.  The 
curves,  it  will  be  noticed,  are  bowed  in  opposite  ways. 
The  bowed  effect  is  due  in  part  to  Mercator's  projec- 
tion ;  in  part  it  may  represent  a  real  decrease  in  speed 
with  time.  But  what  is  strikingly  noticeable  is  the 
opposite  character  of  the  advance  to  the  right,  the  one 
curve  running  up  the  disk,  the  other  down  it.  This 
shows  that  the  development  of  vegetation  proceeded  in 
opposite  directions  over  the  surface. 

Thus  is  the  opposed  action  upon  the  two  planets 
accounted  for,  and  we  are  led  to  the  conclusion  that 
the  canals  are  strips  of  vegetation  fed  by  water  from 
the  polar  caps,  and  that  the  floral  seasons  there  as 
affecting  the  canals  are  conditioned,  not  as  they  would 
be  with  us,  directly  upon  the  return  of  the  sun,  but  in- 
directly so  through  its  direct  effect  upon  the  polar  snows. 

Once  adventured  on  the  idea  of  vegetation,  we  find 
that  it  explains  much  more  than  the  time  taken 
by  the  wave  of  canal-development  down  the  disk.  It 
accounts  at  once  for  the  behavior  of  the  canals  in  the 
three  northern  zones :  the  polar,  arctic,  and  sub-arctic. 
The  mean  cartouches  of  these  three  zones  dip  down 
at  their  latter  end  instead  of  rising  there,  as  is  the  case 
with  the  cartouches  of  the  mean  canals  farther  south. 
This  dip  denotes  that  the  most  northern  canals  were 
waning  already  by  the  middle  of  their  August,  though 


CHAP,  xxvm      CONSTITUTION   OF  CANALS  345 

the  others  showed  no  such  tendency ;  while  the  date  of 
the  deposition  of  the  frost  in  these  northern  latitudes 
shows  that  they  were  started  upon  their  course  toward 
extinction  before  the  snow  itself  had  covered  them.  In 
other  words,  they  were  not  obliterated  but  snuffed  out. 
That  their  decline  was  thus  preparatory  to  the  coming 
of  the  first  snowfall  or  frost-fall,  sufficiently  severe  to 
whiten  the  ground  so  that  it  did  not  melt  the  next 
day,  is  suggestive  of  their  constitution.  It  is  clear 
that  they  were  not  abruptly  cut  off  by  the  frost,  but 
were  timed  by  nature  to  such  extinction.  Vegetation 
would  behave  in  just  this  way,  since  evolution  would 
accommodate  the  career  of  a  plant  to  its  environment. 
The  first  question  to  present  itself  chronologically  in 
the  canals'  annual  history  is  connected  with  the  size 
of  the  cap.  Unfortunately  for  the  simplicity  of  the 
phenomena,  the  cap  is  not  an  extensionless  source  of 
flow,  but  an  extended  surface  melting  from  the  outer 
edge  in.  It  would  seem,  therefore,  that  water  liberated 
from  the  outer  parts  should  have  an  effect  before  the 
main  body  of  it  were  ready  to  begin  its  general  march 
down  the  disk.  There  should  be,  one  would  think, 
at  least  a  partial  action,  locally,  before  the  main  action 
got  under  way.  Now,  there  are  certain  canals  that 
show  cartouches  increasing  apparently  from  the  time 
observations  began,  and  the  most  pronounced  is  the 
Jaxartes,  which  lies  of  all  the  canals  observed  the  farthest 


346  MAES  AND  ITS  CANALS         CHAP,  xxvm 

north.  Now,  the  cartouches  were  founded  on  canals 
quickened  from  the  north  polar  cap.  The  farther  north 
the  canal,  therefore,  the  greater  the  likelihood  of  its 
showing  the  phenomena. 

That  we  note  such  canals  is  therefore  not  only  not 
subversive,  but  actually  corroboratory,  of  the  law  it 
seems  at  first  to  shake.  That  all  the  canals  of  these 
zones  do  not  show  a  like  cartouche-profile  is  not  neces- 
sary, a  part  of  them  being  dependent,  not  upon  the 
earlier,  but  upon  the  later  liberated  flow,  and  thus  par- 
taking in  the  general  law,  which  grows  uniform  lower 
down  the  latitudes. 

As  the  action  from  one  polar  cap  proceeds,  not  only 
down  to  the  equator,  but  across  it  into  the  planet's 
other  hemisphere,  it  appears  that  much,  at  least,  of  the 
surface  of  Mars  has  two  seasons  of  vegetal  growth,  the 
one  quickened  of  the  north  polar  cap,  the  other  of 
the  southern.  How  far  the  polar  spheres  of  action 
overlap  it  is  not  possible  at  present  to  affirm,  as  the 
canals  at  this  opposition  were  only  visible  to  35°  south 
latitude.  That  the  north  polar  quickening  goes  down 
•so  far  is  vouched  for,  and  it  is  probable  from  other 
observed  phenomena  that  it  goes  farther. 

The  alternate  semi-annual  quickening  also  discloses 
itself  directly  in  the  cartouches ;  the  previous  semestral 
growth  from  the  south  polar  cap  actually  showing  in 
them  before  the  impulse  from  the  north  began.  The 


CHAP,  xxvin      CONSTITUTION   OF  CANALS  347 

slow  falling  of  their  curves  to  the  minimum  preceding 
their  later  rise  is  nothing  less  than  the  dying  out  of  the 
effect  started  six  months  before  from  the  south.  The 
gentler  gradient  of  their  fall  proclaims  a  gradual  lapse, 
just  as  the  subsequent  sharper  rise  points  to  the  advent 
of  a  fresh  impulse.  And  this  deduction  seems  to  be 
borne  out  by  another  circumstance.  There  is  some 
evidence  of  decrease  in  the  pre-minimal  gradient  south- 
ward. This  is  telling  testimony  to  the  source  whence 
the  impulse  came.  For  if  it  originated  at  the  south  and 
traveled  northward,  the  southern  canals  would  be  the 
first  to  be  affected  and  the  first  to  die  out,  and  thus 
show  a  longer  dead  season,  exhibited  in  the  cartouches 
as  a  more  level  stretch. 

Lastly,  the  explanation  of  the  canals  as  threads  of 
vegetation  fays  in  with  the  one  which  has  been  found  to 
meet  the  requirements  of  the  blue-green  areas;  while 
the  fact  that  they  prove  to  develop  as  they  do,  re- 
versely to  what  would  take  place  on  earth,  is  exactly 
what  all  we  have  latterly  learnt  about  the  surface  con- 
ditions of  the  planet  would  lead  us  to  expect. 

From  what  has  just  been  said  we  see  that  the  latest 
observations  at  Flagstaff  confirm  the  earlier  ones,  and, 
what  is  especially  corroborative,  they  do  so  along  another 
line.  The  former  were  chiefly  static,  the  latter  kine- 
matic. In  other  words,  the  behavior  of  the  canals  in  ac- 
tion bears  out  the  testimony  of  their  appearance  at  rest. 


CHAPTER  XXIX 

LIFE 

OTUDY  of  the  fundamental  features  of  Martian 
topography  has  disclosed,  as  we  have  seen,  the 
existence  of  vegetation  on  the  planet  as  the  only  ra- 
tional explanation  of  the  dark  markings  there,  con- 
sidered not  simply  on  the  score  of  their  appearance 
momentarily,  but  judged  by  the  changes  that  appear- 
ance undergoes  at  successive  seasons  of  the  Martian 
year.  Thus  we  are  assured  that  plant  life  exists  on  the 
planet.  We  are  made  aware  of  the  fact  in  more  ways 
than  one,  but  most  unanswerably  for  that  trait  to  which 
vegetation  owes  its  very  name,  —  its  periodic  quicken- 
ing to  life.  Thus  the  characteristic  which  has  seemed 
here  most  distinctive  of  this  phase  of  the  organic,  so 
that  man  even  christened  it  in  accordance,  has  proved 
equally  telltale  there. 

Important  as  a  conclusion  this  is  no  less  pregnant  as 
a  premise.  For  the  assurance  that  plant  life  exists  on 
Mars  leads  to  a  further  step  in  extramundane  acquaint- 
ance of  far-reaching  import.  It  introduces  us  at  once 
to  the  probability  of  life  there  of  a  higher  and  more 
immediately  appealing  kind,  not  with  the  vagueness  of 

348 


CHAP,  xxix  LIFE  349 

general  analogy,  but  with  the  definiteness  of  specific 
deduction.  For  the  presence  of  a  flora  is  itself  ground 
for  suspecting  a  fauna. 

Of  a  bond  connecting  the  two  we  get  our  first  hint 
the  moment  we  look  inquiringly  into  the  world  about 
us,  that  of  our  own  earth.  Common  experience  wit- 
nesses to  a  coexistence  which  grows  curious  and  com- 
pelling as  we  consider  it.  For  it  is  not  confined  to  life 
of  any  special  order,  but  ^extends  through  the  whole 
range  of  organisms  of  both  kinds  from  the  lowest  to  the 
highest.  Alga3  and  monera,  orchid  and  mammal,  occur 
side  by  side  and  with  a  certain  considerate  poverty 
or  richness,  as  the  case  may  be.  Luxuriance  in  the  one 
is  matched  by  abundance  in  the  other ;  while  a  scanty 
flora  means  a  poor  fauna.  This  of  which  we  have  been 
aware  in  regions  round  about  us  from  childhood  grows 
in  universality  as  we  explore.  Wherever  man  pene- 
trates out  of  his  proper  sphere  he  finds  the  same  dual 
possession  of  the  land  or  the  sea,  and  a  similar  curtail- 
ing or  expanding  of  both  tenantries  together.  No 
mountain  top  so  cold  but  that  if  it  grow  plants,  it  sup- 
ports insects  and  animals,  too,  after  its  kind ;  no  desert 
so  arid  but  that  creeping  things  find  it  as  possible  a 
habitat  as  life  that  does  not  stir.  Even  in  almost 
boiling  geysers  animalcula  and  confervse  share  and 
share  alike.  Only  where  extreme  conditions  preclude 
the  one  do  they  equally  debar  the  other. 


350  MARS   AND  ITS   CANALS  CHAP,  xxix 

Proceeding  now  from  the  fact  to  its  factors  we  per- 
ceive reasons  for  this  tenure  in  common  of  the  land  by 
the  vegetal  and  animal  kingdoms.  Examination  proves 
the  two  great  divisions  of  the  organic  to  be  inextricably 
connected.  It  strikes  our  notice  first  in  the  relation 
of  plants  to  animals.  It  is  of  everyday  notoriety  that 
animals  eat  plants,  though  it  is  less  universally  under- 
stood that  in  the  ultimate  they  exist  on  nothing  else. 
Plants  furnish  the  food  of  animals ;  not  as  a  matter  of 
partial  preference  but  of  fundamental  necessity.  For 
the  plant  is  the  indispensable  intermediary  in  the  pro- 
cess of  metabolism.  Without  plants  animals  would 
soon  cease  to  exist,  since  they  are  unable  to  manufacture 
their  own  plasm  out  of  the  raw  material  offered  by  in- 
organic nature.  They  must  make  it  out  of  the  already 
prepared  plasm  of  plants  or  out  of  other  animals  who 
have  made  it  from  plants.  So  that  in  the  end  it  all 
comes  back  to  plant  production.  The  plant  is  able  to 
build  its  plasm  out  of  chemical  substances ;  the  animal 
cannot,  except  in  the  case  of  the  nitro-bacteria,  begin 
thus  at  the  lowest  rung  of  the  alimentary  ladder. 

But  the  converse  of  this  dependence  is  also  largely 
true.  Plants  are  beholden  to  animals  for  processes 
that  in  return  make  their  own  life  possible.  The  latter 
minister  to  the  former  with  unconscious  service  all  the 
time,  and  with  no  more  arrogant  independence  than  do 
our  domestics  generally  nowadays.  The  inconspicuous 


CHAP,  xxix  LIFE  351 

earthworm  is  the  fieldhand  of  nature's  crops,  who  gets 
his  own  living  by  making  theirs.  Without  this  day 
and  night  laborer  the  soil  for  want  of  stirring  had 
remained  less  capable  of  grass.  Above  ground  it  is  the 
same  story.  Deprived  of  the  ministrations  of  insects 
many  kinds  of  plants  would  incontinently  perish.  By 
the  solicited  visits  of  bees  and  other  hymenoptera  — 
what  generically  may  be  classed  by  the  layman  as 
flutter-bys  —  is  the  plant's  propagation  made  possible. 
Peculiarly  well  named,  indeed,  are  the  hymenoptera, 
seeing  that  they  are  the  great  matrimonial  go-betweens, 
carrying  pollen  from  one  individual  to  another  and  thus 
uniting  what  otherwise  could  not  meet.  Spectacular 
as  this  widespread  commerce  is,  it  forms  but  portion  of 
the  daily  drama  in  which  animals  and  plants  alike  take 
part.  From  forthright  bargainings  of  honey  for  help, 
we  pass  to  less  direct  but  no  less  effective  alliance  where 
plants  are  beholden  to  animals  for  life  by  the  killing 
of  their  enemies  or  the  weeding-out  of  their  competitors, 
and  from  this  to  generic  furtherance  where  the  inter- 
dependence becomes  broadcast.  In  the  matter  of 
metabolism  the  advantage  is  not  all  upon  one  side. 
In  the  katabolic  process  of  that  which  each  discards 
are  the  two  classes  of  life  mutually  complimentary,  — 
the  waste  of  the  one  being  the  want  of  the  other,  — 
carbonic  acid  gas  being  given  off  by  the  animal,  oxygen 
by  the  plant.  In  biologic  economy  it  is  daily  more 


352  MARS  AND  ITS   CANALS  CHAP,  xxix 

demonstrable  that  both  are  necessary  constituents  to 
an  advancing  whole,  and  that  each  pays  for  what  it  gets 
by  what  it  gives  in  return. 

That  they  are  thus  ancillary  as  well  as  coexistent  to- 
day leads  us  to  confront  for  them  a  community  of  origin 
in  the  past;  and  further  study  confirms  the  inference. 
Both  paleontology  and  entomology,  or  the  science  of 
the  aged  and  the  science  of  the  young,  prove  such  an- 
cestry to  be  a  fact.  By  going  back  from  the  present 
into  the  past,  or,  what  amounts  to  substantially  the 
same  thing,  by  descending  in  the  scale  of  life  to  the 
lowest  known  forms  of  organism,  we  find  proof  of  con- 
comitance, cogent  because  congenital.  At  the  time 
when  inorganic  chemical  compounds  first  passed  by 
evolution  into  organic  ones,  the  change  was  of  so  general 
a  character  that  even  such  tardy  representatives  of  it 
as  survive  today  tax  erudition  to  tell  to  which  of  the 
two  great  kingdoms  they  belong,  the  vegetal  or  the 
animal.  Simplest  and  most  primitive  of  known  organ- 
isms are  the  chromacea,  unnucleated  single  cells  as 
Haeckel  has  shown,  and  next  to  them  in  order  come 
many  of  the  bacteria,  also  of  simple  unnucleated  plasm. 
So  little  do  the  majority  of  the  bacteria  differ  mor- 
phologically from  the  chromacea,  that  on  the  score  of 
structure  the  two  are  not  to  be  catalogued  apart.  Both 
are  as  elemental  as  anything  well  can  be,  which  only 
their  diet  serves  to  divide.  Each  is  an  organism  with- 


CHAP,  xxix  LIFE  353 

out  organs,  thus  belying  the  dictionary  definition  of 
both  animals  and  plants.  Etymologically  they  are  not 
organic  yet  manifestly  are  alive,  and  only  in  their  action 
are  unlike.  The  chromacea  are  plasm-forming  beings, 
and  therefore  they  are  plants ;  the  bacteria  are  plasm- 
eating  beings,  and  so  are  animals.  Even  this  distinc- 
tion is  not  always  preserved.  As  Haeckel  tells  us: 
"  the  nitro-bacteria  which  dwell  in  the  earth  having  the 
vegetal  property  of  converting  ammonia  by  oxidation 
into  nitrous  acid  and  this  into  nitric  acid,  using  as  their 
source  of  carbon  the  carbonic  acid  gas  of  the  atmos- 
phere. They  feed,  like  the  chromacea,  on  simple  in- 
organic compounds."  Here,  then,  we  have,  close  to 
the  threshold  of  organic  life,  unorganized  organisms, 
roughly  speaking  coeval  and  differing  in  a  sense  but 
little,  either  of  them,  from  inorganic  crystals ;  and  yet 
the  one  is  an  animal,  the  other  a  plant.  Progenitors 
of  the  two  great  divisions  of  life,  they  were  themselves 
concomitantly  evolved,  either  side  by  side  or  as  offshoots 
both  of  a  common  stock.  Now,  if  the  ancestors  of  the 
two  great  organic  kingdoms  were  thus  simultaneously 
produced  here,  we  are  warranted  in  believing  that  they 
would  similarly  be  produced  elsewhere,  given  conditions 
suitably  alike.  In  consequence,  if  we  detect  the  pres- 
ence of  the  one,  we  already  have  an  argument  for  infer- 
ring the  other.  Not  to  complete  our  syllogism  would 
be  to  flaunt  a  lack  of  logic  in  nature's  face. 

2  A 


354  MARS  AND  ITS   CANALS  CHAP,  xxix 

Rationally  viewed,  then,  the  general  problem  of  life 
in  other  worlds  reduces  itself  to  a  question  of  condi- 
tions. Since  certain  physical  results  follow  inevitably 
upon  certain  physical  premises,  if  we  can  assure  our- 
selves of  the  proper  premises  we  may  look  to  nature  for 
their  conclusion.  A  priori,  then,  the  possibility  of  life 
becomes  one  of  habitat.  If  the  environment  be 
suitable  life  will  ensue.  What  makes  for  such  a 
mediary  milieu  is,  like  most  cosmic  processes,  in  its 
fundamentals  of  interesting  simplicity ;  for  the  produc- 
tion of  a  proper  nidus  depends  primarily  upon  the  mere 
size  of  the  body  parentally  concerned.  If  a  planet  be 
big  enough  it  will  inevitably  bring  forth  life,  because  of 
conditions  suitable  to  its  generating;  if  too  small  it 
will  remain  sterile  to  the  end  of  time. 

That  size  should  be  the  determining  factor  whether 
a  planet  shall  be  fecund  or  barren  may  seem  at  first 
thought  strange.  Yet  that  it  is  so  admits  of  no  rational 
doubt.  All  that  we  see  of  bodies  about  us  shows  its 
truth,  and  what  we  have  learnt  of  cosmic  process  enables 
us  in  some  sort  to  discern  why.  In  order  for  evolution, 
such  as  we  mark  it  upon  the  earth,  to  be  possible,  the 
parent  body  must  have  been  at  one  time  at  a  high  tem- 
perature, since  only  under  great  heat  can  the  primal 
processes  occur.  But  for  this  generation  of  caloric 
the  aggregate  mass  of  the  particles,  the  falling  together 
of  which  makes  the  planet,  and  their  stoppage  its  inter- 


CHAP,  xxix  LIFE  355 

nal  heat,  must  be  large.  The  sun's  rays  alone  are  insuf- 
ficient to  cause  the  necessary  temperature;  the  heat 
must  come  from  within,  though  it  be  helped  from  with- 
out. Even  here  the  action  is  abetted  by  a  large  body. 
For  a  planet  to  entrap  the  sun's  rays  or  even  to  preserve 
its  own  internal  warmth,  an  atmosphere  is  needed,  and 
it  takes  a  large  body  to  retain  an  atmospheric  covering 
sufficiently  long.  Yet  without  it  not  only  would  there 
be  no  suitable  state,  but  no  medium  -in  which  organic 
or  even  inorganic  reactions  could  go  on.  Lastly, 
water,  the  essential  nidus  for  the  organism's  early 
stages,  has  its  presence  similarly  conditioned.  For  this, 
like  the  atmosphere,  would  from  a  small  body  speedily 
vanish  away.  Thus  the  planet  itself  is  the  life-pro- 
ducing body,  although  the  sun  furthers  the  process 
when  once  begun. 

That  the  needed  substances  are  planetarily  present, 
what  we  know  of  the  distribution  of  matter  astronomi- 
cally sufficiently  attests.  What  we  find  in  meteorites 
shows  that  the  catastrophe  which  preceded  our  present 
solar  system's  birth  scattered  its  elemental  constitu- 
ents throughout  its  domain,  and  thus  when  they  came  to 
be  gathered  up  again  into  planets  that  these  must  have 
been  materially  the  same.  The  manner,  not  the  matter, 
then,  is  alone  that  about  which  we  are  concerned. 

Now,  if  the  mass  of  matter  gravitating  together  to 
form  a  planet  be  sufficient  to  produce  the  proper  inor- 


356  MARS   AND   ITS   CANALS 


CHAl'.   XXIX 


ganic  conditions,  the  organic  must  follow  as  a  matter  of 
course.  That  the  organic  springs  from  the  inorganic 
is  not  only  shown  by  what  has  taken  place  on  earth, 
but  is  the  necessary  logical  deduction  from  its  decay 
back  into  the  inorganic  again.  As  Nageli  admirably 
observes:  "The  origin  of  the  organic  from  the  inor- 
ganic is,  in  the  first  place,  not  a  question  of  experience 
and  experiment,  but  a  fact  deduced  from  the  law  of 
the  constancy  of  matter  and  force.  If  all  things  in  the 
material  world  are  causally  related,  if  all  phenomena 
proceed  on  natural  principles,  organisms  which  are 
formed  of  and  decay  into  the  same  matter  must  have 
been  derived  originally  from  inorganic  compounds." 

The  original  oneness  of  the  two,  the  fact  that  the 
organic  sprang  from  the  inorganic,  is  shown  by  the 
cousinly  closeness  of  the  lowest  organic  with  the  high- 
est inorganic  substances.  The  monera  are  suggestive 
of  crystals  in  their  uniformity  of  structure.  Both 
are  homogeneous  or  approximately  so.  Again,  both 
grow  by  taking  from  what  they  come  in  contact  with 
that  which  they  find  suitable  and  so  add  to  their  body 
by  homogeneous  accretion.  Finally,  when  grown  too 
large  for  single  life,  they  part  into  similar  crystals  or 
split  into  identical  cells.  The  difference  between  the 
division  of  the  crystal  and  the  fission  of  the  cell  is 
small  in  kind ;  much  less  than  that  later  differentiation 
in  genesis  into  parthenogenesis  and  sexual  reproduc- 


CHAP,  xxix  LIFE  357 

tion.  Yet  here  we  unhesitatingly  trace  an  assured  re- 
lationship. It  were  straining  at  a  gnat  to  swallow  a 
camel  to  doubt  it  in  the  other. 

Just  as  the  two  behave  analogically  alike  in  their 
own  action,  so  do  they  observe  a  like  attitude  toward 
nature.  They  thus  point  to  their  common  origin. 
The  monera  are  resemblant  of  chemical  compounds  in 
their  superiority  to  external  influences.  To  outward 
conditions  of  temperature  and  humidity  the  chromacea 
are  much  as  sticks  and  stones.  Some  species  may  re- 
main for  long  frozen  in  ice,  Haeckel  observes,  and  yet 
wake  to  activity  so  soon  as  it  thaws.  Others  may  be 
completely  desiccated,  and  then  resume  their  life  when 
put  in  water  after  a  lapse  of  several  years.  Thus  both 
in  their  deathlike  lives  and  in  their  living  immortality 
the  chromacea  are  close  to  inorganic  things. 

From  preference,  however,  these  lowest  forms  of  life 
affect  what  to  us  would  be  unbearable  temperatures. 
Many  of  the  chromacea  live  in  hot  springs  at  tempera- 
tures of  123°  to  176°  Fahrenheit,  in  which  no  other, 
that  is,  no  higher,  organism  can  dwell.  This  choice  of 
habitat  is  in  line  with  the  other  details  of  their  evolu- 
tionary career.  For  it,  too,  is  in  keeping  with  the  con- 
ditions of  crystalline  growth,  halfway  as  it  were  on  the 
road  to  them;  the  forming  of  crystals  beginning  at  a 
temperature  higher  still.  And  we  perceive  from  it 
that  the  passing  of  the  inorganic  into  the  organic  is 


358  MARS  AND  ITS  CANALS  CHAP,  xxix 

brought  about  by  a  lowering  of  the  temperature  of  the 
parent  planet.  This  again,  is  in  line  with  the  evolu- 
tion of  chemical  complexity.  Let  the  heat  become  less, 
and  higher  and  higher  chemical  compounds,  finally 
the  organic  ones,  become  possible.  That  evolution  is 
nothing  else  than  such  a  gradually  increasing  chemical 
synthesis  is  forced  on  one  by  study  of  the  facts.  Once 
started,  life,  as  paleontology  shows,  develops  along 
both  the  floral  and  the  faunal  lines  side  by  side,  taking 
on  complexity  with  time.  It  begins  so  soon  as  secular 
cooling  has  condensed  water  vapor  to  its  liquid  state ; 
chromacea  and  conferva?  coming  into  being  high  up 
toward  the  boiling-point.  Then,  with  lowering  tem- 
perature come  the  seaweeds  and  the  rhizopods,  then 
the  land  plants  and  the  lunged  vertebrates.  Hand  in 
hand  the  fauna  and  flora  climb  to  more  intricate  per- 
fecting, life  rising  as  temperature  lowers. 

We  perceive  then  that,  considered  a  priori,  the  possi- 
bility of  life  on  a  planet  is  merely  a  question  of  the 
planet's  size;  and  then  pursuantly  that  the  character 
of  that  life  is  a  matter  of  the  planet's  age.  But  age 
again  is  a  question  of  size.  For  the  smaller  its  mass  the 
quicker  the  body  cools,  and  with  a  planet,  growing  cold 
means  growing  old.  *  Within  the  bounds  that  make  life 
possible,  the  smaller  the  body  the  quicker  it  ages  and 
the  more  advanced  its  denizens  must  be.  f  Just  how  far 
the  advance  goes  we  may  not  assert  dogmatically  in 


CHAP,  xxix  LIFE  359 

a  given  case,  since  not  relative  age  alone  but  absolute 
time  as  well  is  concerned  in  it.  It  may  be  that  nature's 
processes  cannot  be  hurried,  and  that  for  want  of  time 
development  may  in  part  be  missed.  But  from  general 
considerations  the  limit  of  the  time  needed  seems  well 
within  most  planetary  careers. 

Now,  the  aspect  of  the  surface  of  Mars  shows  that 
both  these  conditions  have  been  fulfilled.  Mars  is 
large  enough  to  have  begotten  vegetation  and  small 
enough  to  be  already  old.  All  that  we  know  of  the 
physical  state  of  the  planet  points  to  the  possibility 
of  both  vegetal  and  animal  life  existing  there,  and  fur- 
thermore, that  this  life  should  be  of  a  relatively  high 
order  is  possible.  Nothing  contradicts  this,  and  the 
observations  of  the  last  ten  years  have  rendered  the 
conclusion  then  advanced  only  the  more  conclusive. 
Even  the  evidence  of  the  past  state  of  the  planet  con- 
firms that  given  by  its  present  one.  That  with  us  life 
came  out  of  the  seas  finds  its  possible  parallel  in  the 
fact  that  seas  seem  once  to  have  existed  there,  leaving 
their  mark  discernible  to-day.  Life,  then,  had  there  as 
here  the  wherewith  to  begin.  That  we  find  air  and 
water  in  both  shows  that  it  had  the  means  to  continue 
once  begun.  That  it  then  ran  a  like  course  is  further 
witnessed  by  what  we  now  detect.  The  necessary 
premises,  then,  are  there.  More  than  this.  One  half 
of  the  conclusion,  vegetal  life,  gives  evidence  of  itself. 


CHAPTER  XXX 

EVIDENCE 

/~\  F  the  existence  of  animal  life  upon  a  far  planet 
any  evidence  must,  of  necessity,  assume  a  differ- 
ent guise  from  what  its  flora  would  present.  Plant  life 
should  be,  as  on  Mars  we  perceive  it  is;  recognizable 
as  part  and  parcel  of  the  main  features  of  the  planet's 
face.  In  no  such  forthright  manner  could  we  expect 
an  animal  revelation.  The  sort  of  testimony  which 
would  render  the  .one  patent  would  leave  the  other 
obstinately  hid. 

So  long  as  animate  life  was  in  the  lowest  sense  ani- 
mal, it  would  not  be  seen  at  all,  though  it  were  as  wide- 
spread as  the  vegetal  life  all  about  it.  Reason  for  this 
lies  in  their  receptive  character.  Plants  are  fixtures; 
where  they  start  they  stay;  while  from  the  nature  of 
their  food,  derived  directly  from  the  soil  and  from  the 
air,  and  conditioned  chiefly  by  warmth  and  moisture, 
like  forms  inhabit  large  areas  and  by  their  massed  effect 
make  far  impression.  With  animals  it  is  otherwise. 
They  feed  by  forage,  from  beetle  to  buffalo,  roaming  the 
land  for  sustenance.  Thus,  both  for  paucity  of  number 
and  from  not  abiding  in  one  stay  they  must  escape  notice 


CHAP,  xxx  EVIDENCE  361 

at  a  distance  such  that  as  individuals  they  fail  to  show; 
to  say  nothing  of  the  fact  that  the  flora  usually  overtop 
the  fauna,  and  so  help  to  hide  the  latter  while  appear- 
ing itself  distinct.  Any  far  view  of  our  earth  gives  in- 
stance of  this.  Seen  from  some  panoramic  height, 
forest  and  moorland  lie  patently  outspread  to  view,  yet 
imagination  is  taxed  to  believe  them  tenanted  at  all. 
Unless  man  have  marred  the  landscape  not  a  sign 
appears  of  any  living  thing..  One  must  be  near  indeed 
to  note  even  such  unusual  sights  as  a  herd  of  buffalo 
in  the  plains  or  those  immense  flights  of  pigeons,  that 
in  former  years  occurred  like  clouds  darkening  the  air. 
From  the  standpoint  of  another  planet,  through  any  such 
direct  showing  animal  existence  would  still  remain  un- 
known. 

Not  until  the  creatures  had  reached  a  certain  phase 
in  evolution  would  their  presence  become  perceptible; 
and  not  then  directly,  but  by  the  results  such  presence 
brought  to  pass.  Occupancy  would  be  first  evidenced 
by  its  imprint  on  the  land;  discernible  thus  initially 
not  so  much  by  the  bodily  as  by  the  mind's  eye.  For 
not  till  the  animal  had  learnt  to  dominate  nature  and 
fashion  it  to  his  needs  and  ends  would  his  existence 
betray  itself.  By  the  transformation  he  wrought  in 
the  landscape  would  he  be  known.  It  is  thus  we 
should  make  our  own  far  acquaintance;  and  by  the 
disarrangement  of  nature  first  have  inkling  of  man. 


362  MARS  AND  ITS  CANALS  CHAP,  xxx 

That  it  is  thus  we  should  betray  ourselves,  a  consider- 
ation of  man's  history  will  show.  While  he  still  re- 
mained of  savage  simplicity,  a  mere  child  of  nature,  he 
might  come  and  go  unmarked  by  an  outsider,  but  so 
soon  as  he  started  in  to  possess  the  earth  his  handicraft 
would  reveal  him.  From  the  moment  he  bethought 
him  to  till  the  ground,  he  entered  upon  a  course  of 
world-subjugation  of  which  we  cannot  foresee  the  end; 
but  he  has  already  advanced  far  enough  to  give  us  an 
idea  of  the  process.  It  began  with  agriculture.  De- 
forestation with  its  subsequent  quartering  of  crops 
signalized  his  acquisition  of  real  estate.  His  impress 
at  first  was  sporadic  and  irregular,  and  in  so  far  fol- 
lowed that  of  nature  itself ;  but  as  it  advanced  it  took 
on  a  methodism  of  plan.  Husbandry  begot  thrift, 
and  augmented  wants  demanded  an  increasing  return 
for  toil ;  and  to  this  desirable  end  systematization  be- 
came a  necessity.  At  the  same  time  gregariousness 
grew  and  still  further  emphasized  the  need  for  economy 
of  space  and  time.  In  part  unconsciously,  man  learnt 
the  laws  that  govern  the  expenditure  of  force  and  more 
and  more  consciously  applied  them.  Geometry,  un- 
loosed of  Euclid,  became  a  part  of  everyday  life  as  in- 
sidiously as  M.  Jourdain  found  that  he  had  been  talking 
prose.  Regularity  rules  to-day,  to  the  lament  of  art. 
The  railroad  is  straighter  than  the  turnpike,  as  that  is 
straighter  than  the  trail.  Communication  is  now  too 


CHAP,  xxx  EVIDENCE  363 

urgent  in  its  demands  to  know  anything  but  law  and 
take  other  than  the  shortest  path  to  its  destination. 
Tillage  has  undergone  a  like  rectification.  To  one  used 
to  the  patchwork  quilting  of  the  crops  in  older  lands 
the  methodical  rectangles  of  the  farms  of  the  Great 
West  are  painfully  exact.  Yet  it  is  more  than  probable 
that  these  material  manifestations  would  be  the  first 
signs  of  intelligence  to  one  considering  the  earth  from 
far.  Our  towns  would  in  all  likelihood  constitute  the 
next ;  and,  lastly,  the  great  arteries  of  travel  that  min- 
ister to  their  wants.  Their  scale,  too,  would  render 
them  the  first  objects  to  be  observed.  Farming  as  now 
practiced  in  Kansas  or  Dakota  gives  it  a  certain  cos- 
mical  concern ;  fields  for  miles  turning  in  hue  with  the 
rhythm  of  the  drilled  should  impress  an  eye,  if  armed 
with  our  appliances,  many  millions  of  miles  away. 

Even  now  we  should  know  ourselves  cosmically  by 
our  geometrical  designs.  To  interplanetary  under- 
standing it  is  this  quality  that  would  speak.  Still  more 
so  will  it  tell  as  time  goes  on.  As  yet  we  are  but  at  the 
beginning  of  our  subjugation  of  the  globe.  We  have 
hardly  explored  it  all,  still  less  occupied  it.  When  we 
do  so,  and  space  shall  have  become  enhancedly  precious, 
directness  of  purpose  with  economy  of  result  will  have 
partitioned  so  regularly  the  surface  of  the  earth  as  to 
impart  to  it  an  artificiality  of  appearance,  and  it  becomes 
one  vast  coordinated  expanse  subservient  entirely  to 


364  MAES  AND  ITS  CANALS  CHAP,  xxx 

the  wants  of  its  possessors.  Centres  of  population 
and  lines  of  communication,  with  tillage  carried  on  in 
the  most  economic  way ;  to  this  it  must  come  in  the 
end. 

Nor  is  this  outcome  in  any  sense  a  circumstance  acci- 
dental to  the  earth ;  it  is  an  inevitable  phase  in  the  evo- 
lution of  organisms.  As  the  organism  develops  brain 
it  is  able  to  circumvent  the  adversities  of  condition; 
and  by  overcoming  more  pronounced  inhospitality  of 
environment  not  only  to  survive  but  spread.  Evi- 
dence of  this  thought  will  be  stamped  more  and  more 
visibly  upon  the  face  of  its  habitat.  On  earth,  for 
all  our  pride  of  intellect,  we  have  not  yet  progressed 
very  far  from  the  lowly  animal  state  that  leaves  no  rec- 
ords of  itself.  It  is  only  in  the  last  two  centuries  that 
our  self-registration  upon  our  surroundings  has  been 
marked.  With  another  planet  the  like  course  must  in 
all  probability  be  pursued,  and  the  older  the  life  rela- 
tively to  its  habitat  the  more  its  signs  of  occupation 
should  show.  Intelligence  on  other  worlds  could  then 
only  make  its  presence  known  by  such  material  revela- 
tion, and  the  sign-manuals  of  itself  would  appear  more 
artificial  in  look  as  that  life  was  high  in  rank.  Given 
the  certainty  of  plant-life,  such  markings  are  what  one 
would  look  to  find.  Criticism  which  refuses  to  credit 
detail  of  the  sort  because  too  bizarre  to  be  true  writes 
itself  down  as  unacquainted  with  the  character  of  the 


CHAP,  xxx  EVIDENCE  365 

problem.  For  it  is  precisely  such  detail  which  should 
show  if  any  evidence  at  all  were  forthcoming. 

If,  now,  we  turn  our  inquiry  to  Mars,  we  shall  be 
fairly  startled  at  what  its  disk  discloses.  For  we  find 
ourselves  confronted  in  the  canals  and  oases  by  pre- 
cisely the  appearances  a  priori  reasoning  proves  should 
show  were  the  planet  inhabited.  Our  abstract  prog- 
nostications have  taken  concrete  form.  Here  in  these 
rectilineal  lines  and  roundish  spots  we  have  spread  out 
our  centres  of  effort  and  our  lines  of  communication. 
For  the  oases  are  clearly  ganglia  to  which  the  canals 
play  the  part  of  nerves.  The  strange  geometricism 
which  proves  inexplicable  on  any  other  hypothesis  now 
shows  itself  of  the  essence  of  the  solution.  The  ap- 
pearance of  artificiality  cast  up  at  the  phenomena  in 
disproof  vindicates  itself  as  the  vital  point  in  the  whole 
matter.  Like  the  cachet  of  an  architect,  it  is  the  thing 
about  the  building  that  established  the  authorship. 

Though  the  Earth  and  Mars  agree  in  being  planets, 
they  differ  constitutionally  in  several  important  re- 
spects. Even  to  us  the  curious  network  that  en- 
shrouds the  Martian  disk  suggests  handicraft;  it 
implies  it  much  more  when  considered  from  a  Martian 
standpoint. 


CHAPTER  XXXI 

THE    HUSBANDING   OF    WATER 

^T^HAT  the  canals  and  oases  are  of  artificial  origin 
is  thus  suggested  by  their  very  lookj^when  we 
come  to  go  further  and  inquire  into  what  may  be  their 
office  in  the  planet's  economy,  we  find  that  the  idea  in 
addition  to  its  general  probability  now  acquires  par- 
ticular support.  For  this  we  are  indebted  in  part  to 
study  of  their  static  aspect,  but  chiefly  to  what  has 
been  learnt  of  their  kinematic  action. 

Dearth  of  water  is  the  key  to  their  character.  Water 
is  very  scarce  on  the  planet.  We  know  this  by  the 
absence  of  any  bodies  of  it  of  any  size  upon  the  surface. 
So  far  as  we  can  see  the  only  available  water  is  what 
comes  from  the  semi-annual  melting  at  one  or  the  other 
cap  of  the  snow  accumulated  there  during  the  previous 
winter.  Beyond  this  there  is  none  except  for  what 
may  be  present  in  the  air.  Now,  water  is  absolutely 
essential  to  all  forms  of  life;  no  organisms  can  exist 
without  it. 

But  as  a  planet  ages,  it  loses  its  oceans  as  has  before 
been  explained,  and  gradually  its  whole  water  supply. 
Life  upon  its  surface  is  confronted  by  a  growing  scarcity 

366 


CHAP,  xxxi     THE   HUSBANDING  OF  WATER  367 

of  this  essential  to  existence.  For  its  fauna  to  survive 
it  must  utilize  all  it  can  get.  To  this  end  it  would  be 
obliged  to  put  forth  its  chief  endeavors,  and  the  out- 
come of  such  work  would  result  in  a  deformation  of  the 
disk  indicative  of  its  presence.  Lines  of  communica- 
tion for  water  purposes,  between  the  polar  caps,  on  the 
one  hand,  and  the  centres  of  population,  on  the  other, 
would  be  the  artificial  markings  we  should  expect  to 
perceive. 

f  Now,  it  is  not  a  little  startling  that  the  semblance  of 
just  such  signs  of  intelligent  interference  with  nature  is 
what  we  discern  on  the  face  of  Mars,  —  in  the  canals' 
and  oases.  So  dominant  in  its  mien  is  the  pencil-like 
directness  of  the  canals  as  to  be  the  trait  that  primarily 
strikes  an  unprejudiced  observer  who  beholds  this  as- 
tounding system  of  lines  under  favorable  definition 
for  the  first  time,  and  its  impressiveness  only  grows 
on  him  with  study  of  the  phenomena.  That  they 
suggested  rule  and  compass,  Schiaparelli  said  of  them 
long  ago,  without  committing  himself  as  to  what  they 
were.  In  perception  the  great  observer  was,  as  usual, 
quite  right ;  and  the  better  they  are  seen  the  more  they 
justify  the  statement.  Punctilious  in  their  precision, 
they  outdo  in  method  all  attempts  of  freehand  drawing 
to  copy  them.  Often  has  the  writer  tried  to  represent 
the  regularity  he  saw,  only  to  draw  and  redraw  his  lines 
in  vain.  Nothing  short  of  ruling  them  could  have 


368  MARS  AND   ITS   CANALS  CHAP,  xxxi 

reproduced  what  the  telescope  revealed.  Strange 
as  their  depiction  may  look  in  the  drawings,  the 
originals  look  stranger  still.  Indeed,  that  they  should 
look  unnatural  when  properly  depicted  is  not  unnatural 
if  they  are  so  in  fact.  For  it  is  the  geodetic  precision 
which  the  lines  exhibit  that  instantly  stamps  them 
to  consciousness  as  artificial.  The  inference  is  so 
forthright  as  to  be  shared  by  those  who  have  not 
seen  them  to  the  extent  of  instant  denial  of  their 
objectivity.  Drawings  of  them  look  too  strange  to  be 
true.  So  scepticism  imputes  to  the  draughtsman 
their  artificial  fashioning,  not  realizing  that  by  so  doing 
it  bears  unconscious  witness  to  their  character.  For 
in  order  to  disprove  the  deduction  it  is  driven  to  deny 
the  fact.  Now  the  fact  can  look  after  itself  and  will 
be  recognized  in  time.  For  that  the  lines  are  as  I  have 
stated  is  beyond  doubt.  Each  return  of  the  planet 
shows  them  more  and  more  geometric  as  sites  are 
bettered  and  training  improves. 

Suggestive  of  design  as  their  initial  appearance  is, 
the  idea  of  artificiality  receives  further  sanction  from 
more  careful  consideration,  even  from  a  static  point 
of  view,  on  at  least  eight  counts :  — 

1.  Their  straightness ; 

2.  Their  individually  uniform  size; 

3.  Their  extreme  tenuity; 

4.  The  dual  character  of  some  of  them ; 


CHAP,  xxxi     THE   HUSBANDING   OF  WATER  369 

5.  Their  position  with  regard  to  the  planet's  funda- 
mental features; 

6.  Their  relation  to  the  oases ; 

7.  The  character  of  these  spots ;  and,  finally, 

8.  The  systematic  networking  by  both  canals  and 
spots  of  the  whole  surface  of  the  planet. 

Now,  no  natural  phenomena  within  our  knowledge 
show  such  regularity  on  such  a  scale  upon  any  one  of 
these  eight  counts,  a  fortiori  upon  all.  When  one  con- 
siders that  these  lines  run  for  thousands  of  miles  in  an 
unswerving  direction,  as  far  relatively  as  from  London 
to  Bombay,  and  as  far  actually  as  from  Boston  to  San 
Francisco,  the  inadequacy  of  natural  explanation 
becomes  glaring. 

These  several  counts  become  more  expressive  of  de- 
sign the  farther  one  looks  into  them.  Straightness 
upon  a  sphere  means  the  following  of  an  arc  of  a  great 
circle.  The  lines,  then,  are  arcs  of  great  circles.  Now, 
the  great  circle  course  is  the  shortest  distance  connect- 
ing two  given  points.  The  canals  of  Mars,  then,  prac- 
tice this  economy;  they  connect  their  terminals  by 
the  shortest,  that  is,  other  things  equal,  by  the  quick- 
est and  least  wasteful  path.  Their  preserving  a  uni- 
form width  throughout  this  distance  is  an  equally  un- 
natural feature  for  any  natural  action  to  exhibit,  but 
a  perfectly  natural  one  for  an  unnatural  agent.  For 
means  of  communication  for  whatever  cause  would 

2B 


370  MAKS  AND  ITS  CANALS  CHAP,  xxxi 

probably  be  fashioned  of  like  countenance  throughout. 
Their  extreme  tenuity  is  a  third  trait  pointing  to  ar- 
tificiality; inasmuch  as  the  narrower  they  are,  the 
more  probable  is  their  construction  by  local  intelli- 
gence. Even  more  inexplicable,  except  from  intent, 
is  their  dual  character.  For  them  to  parallel  one 
another  like  the  twin  rails  of  a  railway  track,  seems 
quite  beyond  the  powers  of  natural  causation.  Enig- 
matic, indeed,  from  a  natural  standpoint,  they  cease 
to  be  so  enigmatic  viewed  from  an  artificial  one;  and 
this  the  more  by  reason  of  what  has  lately  been  learnt 
of  the  character  of  their  distribution.  That  they  are 
found  most  plentifully  near  the  equator,  where  the  lati- 
tudinal girth  is  greatest,  and  thence  diminish  in  num- 
bers to  about  latitude  60°,  where  they  disappear,  — 
and  this  not  relatively  to  the  amount  of  surface  but 
actually, —  is  very  significant.  It  is  quite  incapable  of 
natural  explanation,  and  can  only  be  accounted  for 
on  some  theory  of  design  such  as  lines  of  communica- 
tion, or  canals  conducting  water  down  the  latitudes  for 
distribution.  So  that  this  distribution  of  the  doubles 
is  in  keeping  with  the  law  of  development  disclosed 
by  the  canals  en  masse.  Channels  and  return-channels 
the  two  lines  of  the  pair  may  be,  but  about  this  we  can 
at  present  posit  nothing.  The  relation  may  be  of 
still  greater  complexity,  and  we  must  carefully  dis- 
tinguish between  surmise  and  deduction. 


CHAP,  xxxi     THE   HUSBANDING   OF  WATER  371 

The  position  of  the  canals,  with  regard  to  the  main 
features  of  the  disk,  has  a  cogency  of  its  own,  an  argu- 
ment from  time.  The  places  from  which  the  lines  start 
and  to  which  they  go  are  such  as  to  imply  a  dependence 
of  the  latter  upon  the  former  chronologically.  The 
lines  are  logically  superposed  upon  the  natural  features ; 
not  as  if  they  had  grown  there,  but  as  if  they  had  been 
placed  there  for  topographic  cause.  Those  termini 
are  used  which  we  should  ourselves  select  for  stations 
of  intercommunication.  For  the  lines  not  only  leave 
important  geodetic  points,  but  they  travel  directly 
to  equally  salient  ones. 

The  connection  of  the  canals  with  the  oases  is  no  less 
telltale  of  intent.  The  spots  are  found  only  at  junc- 
tions, clearly  the  seal  and  sanction  of  such  rendezvous. 
Their  relation  to  the  canals  that  enter  them  bespeaks 
method  and  design.  Centring  single  lines,  they  are 
inclosed  by  doubles,  a  disposition  such  as  would  be 
true  did  they  hold  a  pivotal  position  in  the  planet's 
economy. 

The  shape  of  the  oases  also  suggests  significance. 
Their  form  is  round,  a  solid  circle  of  shading  of  so  deep 
a  tone  as  to  seem  black,  although  undoubtedly  in  truth 
blue-green.  Now,  a  circular  area  has  this  peculiar 
property,  that  it  incloses  for  a  given  length  of  perimeter 
the  maximum  of  space.  Any  other  area  has  a  longer 
inclosing  boundary  for  the  surface  inclosed.  Con- 


372  MAES  AND  ITS   CANALS  CHAP,  xxxi 

sidering  each  area  to  be  made  up  of  onion-like  envelops 
to  an  original  core,  each  similar  in  shape  to  the  kernel, 
we  see  that  the  property  in  question  means  that  the 
average  distance  for  points  of  the  circular  area  from 
the  centre  is  less  than  the  same  distance  for  those  of 
any  other  figure.  This  has  immediate  bearing  on  the 
possible  fashioning  of  such  areas.  For  sufficient  intelli- 
gence in  the  fashioners  would  certainly  lead  to  a  con- 
struction, where  the  greatest  area  could  be  attended  to 
at  the  least  expenditure  of  force.  This  would  be  where 
the  distance  to  be  traveled  from  the  centre  to  all  the 
desired  points  was  on  the  average  least;  that  is,  the 
area  would  be  round. 

But  last  and  all-embracing  in  its  import  is  the  system 
which  the  canals  form.  Instead  of  running  at  hap- 
hazard, the  canals  are  interconnected  in  a  most  remark- 
able manner.  They  seek  centres  instead  of  avoiding 
them.  The  centres  are  linked  thus  perfectly  one  with 
another,  an  arrangement  which  could  not  result  from 
centres,  whether  of  explosion  or  otherwise,  which  were 
themselves  discrete.  Furthermore,  the  system  covers 
the  whole  surface  of  the  planet,  dark  areas  and  light 
ones  alike,  a  world-wide  distribution  which  exceeds 
the  bounds  of  natural  possibility.  Any  force  which 
could  act  longitudinally  on  such  a  scale  must  be  limited 
latitudinally  in  its  action,  as  witness  the  belts  of  Jupiter 
or  the  spots  upon  the  sun.  Rotational,  climatic,  or 


CHAP,  xxxi     THE   HUSBANDING   OF  WATER  373 

other  physical  cause  could  not  fail  of  zonal  expression. 
Yet  these  lines  are  grandly  indifferent  to  such  compel- 
ling influences.  Finally,  the  system  after  meshing  the 
surface  in  its  entirety  runs  straight  into  the  polar  caps. 

It  is,  then,  a  system  whose  end  and  aim  is  the  tap- 
ping of  the  snow-cap  for  the  water  there  semiannually 
let  loose ;  then  to  distribute  it  over  the  planet's  face. 

Function  of  this  very  sort  is  evidenced  by  the  look 
of  the  canals.  Further  study  during  the  last  eleven 
years  as  to  their  behavior  leads  to  a  like  conclusion, 
while  at  the  same  time  it  goes  much  farther  by  reveal- 
ing the  action  in  the  case.  This  action  proves  to  be 
not  only  in  accord  with  the  theory,  but  interestingly 
explanatory  of  the  process. 

In  the  first  place,  the  canals  have  shown  themselves, 
as  they  showed  to  Schiaparelli,  to  be  seasonal  phe- 
nomena. This  negatives  afresh  the  possibility  of  their 
being  cracks.  But  furthermore,  their  seasonal  be- 
havior turns  out  to  follow  a  law  quite  different  from 
what  we  know  on  earth  and  betokens  that  they  are  in- 
debted to  the  melting  of  the  polar  cap  for  their  annual 
growth,  even  more  directly  than  to  the  sun,  and  that 
vegetation  is  the  only  thing  that  satisfactorily  accounts 
for  their  conduct.  But  again  this  is  not  all.  Their 
time  of  quickening  proceeds  with  singular  uniformity 
down  the  disk,  not  only  to,  but  across  the  equator. 
Now,  this  last  fact  has  peculiar  significance. 


374  MAES  AND  ITS   CANALS  CHAP,  xxxi 

So  large  are  the  planetary  masses  that  no  substance 
can  resist  the  strains  due  to  the  cosmic  forces  acting 
on  them  to  change  their  shape  till  it  becomes  one  of 
stable  equilibrium.  Thus  a  body  of  planetary  size, 
if  unrotating,  becomes  a  sphere  except  for  solar  tidal 
deformation ;  if  rotating,  it  takes  on  a  spheroidal  form 
exactly  expressive,  as  far  as  observation  goes,  of  the  so- 
called  centrifugal  force  at  work.  Mars  presents  such 
a  figure,  being  flattened  out  to  correspond  to  its  axial 
rotation.  Its  surface,  therefore,  is  in  fluid  equilib- 
rium, or,  in  other  words,  a  particle  of  liquid  at  any 
point  of  its  surface  at  the  present  time  would  stay 
where  it  was,  devoid  of  inclination  to  move  elsewhere. 

Now,  the  water  which  quickens  the  verdure  of  the 
canals  moves  from  the  neighborhood  of  the  pole  down 
to  the  equator  as  the  season  advances.  This  it  does, 
then,  irrespective  of  gravity.  No  natural  force  propels 
it,  and  the  inference  is  forthright  and  inevitable  that  it 
is  artificially  helped  to  its  end.  There  seems  to  be  no 
escape  from  this  deduction.  Water  flows  only  down- 
hill, and  there  is  no  such  thing  as  downhill  on  a  surface 
already  in  fluid  equilibrium.  A  few  canals  might  pre- 
sumably be  so  situated  that  their  flow  could,  by  ine- 
quality of  terrane,  lie  equatorward,  but  not  all.  As  we 
see  on  the  earth,  rivers  flow  impartially  to  all  points  of 
the  compass,  dependent  only  upon  unevenness  of  the 
local  surface  conditions.  Now,  it  is  not  in  particular 


CHAP,  xxxi     THE   HUSBANDING  OF  WATER  375 

but  by  general  consent  that  the  canal  system  of  Mars 
develops  from  pole  to  equator. 

From  the  respective  times  at  which  the  minima  take 
place,  it  appears  that  the  canal-quickening  occupies 
fifty-two  days,  as  evidenced  by  the  successive  vegetal 
darkenings  to  descend  from  latitude  72°  north  to  lati- 
tude 0°,  a  journey,  of  2650  miles.  This  gives  for  the 
water  a  speed  of  fifty-one  miles  a  day,  or  2.1  miles  an 
hour.  The  rate  of  progression  is  remarkably  uniform ; 
and  this  abets  the  deduction  as  to  assisted  transference. 
The  simple  fact  that  it  is  carried  from  near  the  pole  to 
the  equator  is  sufficiently  telltale  of  extrinsic  aid,  but 
the  uniformity  of  the  action  increases  its  significance. 

But  the  fact  is  more  unnatural  yet.  The  growth 
pays  no  regard  to  the  equator,  but  proceeds  across  it 
as  if  it  did  not  exist  into  the  planet's  other  hemisphere. 
Here  is  something  still  more  telling  than  its  travel  to 
this  point.  For  even  if  we  suppose,  for  the  sake  of  ar- 
gument, that  natural  forces  took  the  water  down  to  the 
equator,  their  action  must  there  be  certainly  reversed 
and  the  equator  prove  a  dead-line  to  pass  which  were 
impossible. 


CHAPTER  XXXII 

CONCLUSION 

rjlHAT  Mars  is  inhabited  by  beings  of  some  sort 
•*-"  or  other  we  may  consider  as  certain  as  it  is 
uncertain  what  those  beings  may  be.  The  theory  of  the 
existence  of  intelligent  life  on  Mars  may  be  likened  to 
the  atomic  theory  in  chemistry  in  that  in  both  we  are 
led  to  the  belief  in  units  which  we  are  alike  unable  to 
define.  Both  theories  explain  the  facts  in  their  re- 
spective fields  and  are  the  only  theories  that  do,  while 
as  to  what  an  atom  may  resemble  we  know  as  little  as 
what  a  Martian  may  be  like.  But  the  behavior  of 
chemic  compounds  points  to  the  existence  of  atoms  too 
small  for  us  to  see,  and  in  the  same  way  the  aspect  and 
behavior  of  the  Martian  markings  implies  the  action 
of  agents  too  far  away  to  be  made  out. 

But  though  in  neither  case  can  we  tell  anything  of  the 
bodily  form  of  its  unit,  we  can  in  both  predicate  a  good 
deal  about  their  workings.  Apart  from  the  general 
fact  of  intelligence  implied  by  the  geometric  character 
of  their  constructions,  is  the  evidence  as  to  its  degree 
afforded  by  the  cosmopolitan  extent  of  the  action. 
Girdling  their  globe  and  stretching  from  pole  to  pole, 
the  Martian  canal  system  not  only  embraces  their 


CHAP,  xxxn  CONCLUSION  377 

whole  world,  but  is  an  organized  entity.  Each  canal 
joins  another,  which  in  turn  connects  with  a  third,  and 
so  on  over  the  entire  surface  of  the  planet.  This  con- 
tinuity of  construction  posits  a  community  of  interest. 
Now,  when  we  consider  that  though  not  so  large  as  the 
Earth  the  world  of  Mars  is  one  of  4200  miles  diameter 
and  therefore  containing  something  like  212,000,000 
of  square  miles,  the  unity  of  the  process  acquires 
considerable  significance.  The  supposed  vast  enter- 
prises of  the  earth  look  small  beside  it.  None  of  them 
but  become  local  in  comparison,  gigantic  as  they  seem 
to  us  to  be. 

The  first  thing  that  is  forced  on  us  in  conclusion  is  the 
necessarily  intelligent  and  non-bellicose  character  of 
the  community  which  could  thus  act  as  a  unit  through- 
out its  globe.  War  is  a  survival  among  us  from  savage 
times  and  affects  now  chiefly  the  boyish  and  unthinking 
element  of  the  nation.  The  wisest  realize  that  there 
are  better  ways  for  practicing  heroism  and  other  and 
more  certain  ends  of  insuring  the  survival  of  the  fittest. 
It  is  something  a  people  outgrow.  But  whether  they 
consciously  practice  peace  or  not,  nature  in  its  evolu- 
tion eventually  practices  it  for  them,  and  after  enough 
of  the  inhabitants  of  a  globe  have  killed  each  other  off, 
the  remainder  must  find  it  more  advantageous  to  work 
together  for  the  common  good.  Whether  increasing 
common  sense  or  increasing  necessity  was  the  spur 


378  MAES  AND  ITS   CANALS          CHAP,  xxxn 

that  drove  the  Martians  to  this  eminently  sagacious 
state  we  cannot  say,  but  it  is  certain  that  reached  it  they 
have,  and  equally  certain  that  if  they  had  not  they 
must  all  die.  When  a  planet  has  attained  to  the  age  of 
advancing  decrepitude,  and  the  remnant  of  its  water 
supply  resides  simply  in  its  polar  caps,  these  can  only 
be  effectively  tapped  for  the  benefit  of  the  inhabitants 
when  arctic  and  equatorial  peoples  are  at  one.  Differ- 
ence of  policy  on  the  question  of  the  all-important 
water  supply  means  nothing  short  of  death.  Isolated 
communities  cannot  there  be  sufficient  unto  themselves ; 
they  must  combine  to  solidarity  or  perish. 

From  the  fact,  therefore,  that  the  reticulated  canal 
system  is  an  elaborate  entity  embracing  the  whole  planet 
from  one  pole  to  the  other,  we  have  not  only  proof  of 
the  world-wide  sagacity  of  its  builders,  but  a  very  sug- 
gestive side-light,  to  the  fact  that  only  a  universal  ne- 
cessity such  as  water  could  well  be  its  underlying  cause. 

Possessed  of  important  bearing  upon  the  possibility 
of  life  on  Mars  is  the  rather  recent  appreciation  that  the 
habitat  of  both  plants  and  animals  is  conditioned  not 
by  the  minimum,  nor  by  the  mean  temperature  of  the 
locality,  but  by  the  maximum  heat  attained  in  the  re- 
gion. Not  only  is  the  minimum  thermometric  point 
no  determinator  of  a  dead-line,  but  even  a  mean  tem- 
perature does  not  measure  organic  capability.  The 
reason  for  this  is  that  the  continuance  of  the  species 


CHAP,  xxxn  CONCLUSION  379 

seems  to  depend  solely  upon  the  possibility  of  repro- 
duction, and  this  in  turn  upon  a  suitable  temperature 
at  the  critical  period  of  the  plant's  or  animal's  career. 
Contrary  to  previous  ideas  on  the  subject,  Merriam 
found  this  to  be  the  case  with  the  fauna  of  the  San 
Francisco  Peak  region  in  northern  Arizona.  The 
region  was  peculiarly  fitted  for  a  test,  because 
of  rising  a  boreal  island  of  life  out  of  a  sub- 
tropic  sea  of  desert.  It  thus  reproduced  along  its 
flanks  the  conditions  of  climates  farther  north,  altitude 
taking  the  part  of  latitude,  one  succeeding  another 
until  at  the  top  stood  the  arctic  zone.  Merriam 
showed  that  the  existence  of  life  there  was  dependent 
solely  upon  a  sufficiency  of  warmth  at  the  breeding  sea- 
son. If  that  were  enough  the  animal  or  plant  propa- 
gated its  kind,  and  held  its  foothold  against  adverse 
conditions  during  the  rest  of  the  year.  This  it  did 
by  living  during  its  brief  summer  and  then  going  into 
hibernation  the  balance  of  the  time.  Nature  in  short 
suspended  its  functions  to  a  large  extent  for  months 
together,  enabling  it  to  resurrect  when  the  conditions 
turned. 

Hibernation  proves  thus  to  be  a  trait  acquired  by  the 
organism  in  consequence  of  climatic  conditions.  Like 
all  such  it  can  only  be  developed  in  time,  since  nature 
is  incapable  of  abrupt  transition.  An  animal  suddenly 
transported  from  the  tropic  to  a  sub-arctic  zone  will 


380  MARS   AND  ITS   CANALS  CHAP,  xxxn 

perish,  because  it  has  not  yet  learnt  the  trick  of  winter 
sleeping.  While  still  characterized  by  seasonal  in- 
somnia it  is  incapable  of  storing  its  energies  and  biding 
its  time.  But  given  time  enough  to  acquire  the  art, 
its  existence  is  determined  solely  by  the  enjoyment  of 
,  heat  enough  at  some  season  to  permit  of  the  vital  pos- 
sibility of  reproducing  its  kind. 

Diurnal  shutting  off  of  the  heat  affects  the  process 
but  little,  provided  the  fall  be  not  below  freezing  at  the 
hottest  season.  So  much  is  shown  by  the  fauna  of  our 
arctic  and  sub-arctic  zones,  but  still  more  pertinently  to 
Mars  by  the  zones  of  the  San  Francisco  Peak  region, 
since  the  thinner  air  of  altitude,  through  which  a  greater 
amount  of  heat  can  radiate  off,  is  there  substituted 
for  the  thicker  one  of  latitudinally  equal  isotherms. 
Here  again  with  the  diurnal  as  before  with  the  seasonal 
it  is  the  maximum,  not  the  mean,  or,  till  low,  even  the 
minimum  temperature,  that  tells. 

Now,  with  Mars  the  state  of  things  is  completely  in 
accord  with  what  is  thus  demanded  for  the  existence  of 
life.  The  Martian  climate  is  one  of  extremes,  where 
considerable  heat  treads  on  the  heels  of  great  cold. 
And  the  one  of  these  two  conditions  is  as  certain  as  the 
other,  as  the  condition  of  the  planet's  surface  shows 
conclusively.  In  summer  and  during  the  day  it  must 
be  decidedly  hot,  certainly  well  above  any  possible 
freezing,  a  thinner  air  blanket  actually  increasing  the 


CHAP,  xxxn  CONCLUSION  381 

amount  of  heat  that  reaches  the  surface,  though  affect- 
ing the  length  of  time  of  its  retention  unfavorably. 
The  maximum  temperature,  therefore,  cannot  be  low. 
The  minimum  of  course  is;  but  as  we  have  just  seen, 
it  is  the  maximum  that  regulates  the  possibility  of  life. 
In  spite,  therefore,  of  a  winter  probably  longer  and 
colder  than  our  own,  organic  life  is  not  in  the  least  de- 
barred from  finding  itself  there. 

Indeed,  the  conditions  appear  to  be  such  as  to  put  a 
premium  upon  life  of  a  high  order.  The  Martian  year 
being  twice  as  long  as  our  own,  the  summer  is  there  pro- 
portionately extended.  Even  in  the  southern  hemi- 
sphere, the  one  where  the  summer  is  the  shortest,  it 
lasts  for  158  days,  while  at  the  same  latitudes  our 
own  is  but  90  days.  This  lengthening  of  the  period  of 
reproduction  cannot  but  have  an  elevating  effect  upon 
the  organism  akin  to  the  prolongation  of  childhood 
pointed  out  by  John  Fiske  as  playing  so  important  a 
part  in  the  evolution  of  the  highest  animals.  Day  and 
night,  on  the  other  hand,  alternate  there  with  approxi- 
mately the  same  speed  as  here,  and  except  for  what  is 
due  to  a  thinner  air  covering  reproduce  our  own  ter- 
restrial diurnal  conditions,  which  as  we  saw  are  not 
inimical  to  life. 

In  this  respect,  then,  Mars  proves  to  be  by  no  means 
so  bad  a  habitat.  It  offers  another  example  of  how 
increasing  knowledge  widens  the  domain  that  life  may 


382  MARS   AND  ITS  CANALS  CHAP,  xxxn 

occupy.  Just  as  we  have  now  found  organic  existence 
in  abyssal  depths  of  sea  and  in  excessive  degrees  of  both 
heat  and  cold,  so  do  we  find  from  exploration  of  our 
island  mountains,  which  more  than  any  other  locality 
on  earth  facsimile  the  Martian  surface,  its  possession 
there  as  well. 

Another  point,  too,  is  worth  consideration.  In  an 
aging  world  where  the  conditions  of  life  have  grown 
more  difficult,  mentality  must  characterize  more  and 
more  its  beings  in  order  for  them  to  survive,  and  would 
in  consequence  tend  to  be  evolved.  To  find,  therefore, 
upon  Mars  highly  intelligent  life  is  what  the  planet's 
state  would  lead  one  to  expect. 

To  some  people  it  may  seem  that  the  very  strange- 
ness of  Martian  life  precludes  for  it  an  appeal  to  human 
interest.  To  me  this  is  but  a  near-sighted  view.  The 
less  the  life  there  proves  a  counterpart  of  our  earthly 
state  of  things,  the  more  it  fires  fancy  and  piques  in- 
quiry as  to  what  it  be.  We  all  have  felt  this  impulse 
in  our  childhood  as  our  ancestors  did  before  us,  when 
they  conjured  goblins  and  spirits  from  the  vasty  void, 
and  if  our  energy  continue  we  never  cease  to  feel  its 
force  through  life.  We  but  exchange,  as  our  years  in- 
crease, the  romance  of  fiction  for  the  more  thrilling 
romance  of  fact.  As  we  grow  older  we  demand  reality, 
but  so  this  requisite  be  fulfilled  the  stranger  the  realiza- 
tion the  better  we  are  pleased.  Perhaps  it  is  the  more 


CHAP,  xxxn  CONCLUSION  383 

vivid  imagination  of  youth  that  enables  us  all  then  to 
dispense  with  the  hall-mark  of  actuality  upon  our  cher- 
ished visions ;  perhaps  a  deeper  sense  of  our  own  one- 
ness with  nature  as  we  get  on  makes  us  insist  upon  get- 
ting the  real  thing.  Whatever  the  reason  be,  certain 
it  is  that  with  the  years  a  narration,  no  matter  how 
enthralling,  takes  added  hold  of  us  for  being  true. 
But  though  we  crave  this  solid  foothold  for  our  concep- 
tions, we  yield  on  that  account  no  jot  or  tittle  of  our 
interest  for  the  unexpected. 

Good  reason  we  have  for  the  allurement  we  feel 
toward  what  is  least  like  us.  For  the  wider  the  separa- 
tion from  the  familiar,  the  greater  the  parallax  the  new 
affords  for  cosmic  comprehension.  That  which  differs 
little  yields  little  to  the  knowledge  already  possessed. 
Just  as  a  longer  base  line  gives  us  a  better  measure 
of  the  distance  of  the  sun,  so  here  the  more  diverse  the 
aspects,  the  farther  back  they  push  the  common  start- 
ing-point and  furnish  proportionately  comprehensive 
insight  into  the  course  by  which  each  came  to  be  what 
it  is.  By  studying  others  we  learn  about  ourselves, 
and  though  from  the  remote  we  learn  less  easily,  we 
eventually  learn  the  more.  Even  on  the  side,  then, 
that  touches  most  men,  the  personal,  the  strangeness 
of  the  subject  should  to  the  far-seeing  prove  all  the 
greater  magnet. 

One  of  the  things  that  makes  Mars  of  such  transcen- 


384  MARS   AND   ITS  CANALS          CHAP,  xxxn 

dent  interest  to  man  is  the  foresight  it  affords  of  the 
course  earthly  evolution  is  to  pursue.  On  our  own 
world  we  are  able  only  to  study  our  present  and  our 
past ;  in  Mars  we  are  able  to  glimpse,  in  some  sort,  our 
future.  Different  as  the  course  of  life  on  the  two 
planets  undoubtedly  has  been,  the  one  helps,  however 
imperfectly,  to  better  understanding  of  the  other. 

Another,  more  abstract  but  no  less  alluring,  appeals 
to  that  desire  innate  in  man  to  know  about  the  cosmos 
of  which  he  forms  a  part  and  which  we  call  by  the  name 
of  science.  Study  of  Mars  responds  to  this  craving 
both  directly  by  revelation  of  the  secrets  of  another 
world  and  indirectly  by  the  bearing  of  what  we  thus 
learn  upon  our  understanding  of  the  laws  of  the  uni- 
verse. For  the  facts  thus  acquired  broaden  our  con- 
ceptions in  every  branch  of  science.  Some  day  our 
own  geology,  meteorology,  and  the  rest  will  stand  in- 
debted to  study  of  the  planet  Mars  for  advance  along 
their  respective  lines.  Already  the  most  alert  of  those 
professing  them  are  lending  ear  to  information  from 
this  source,  and  such  cosmopolitanism  can  but  increase 
as  the  years  roll  on.  Today  what  we  already  know  is 
helping  to  comprehension  of  another  world;  in  a  not 
distant  future  we  shall  be  repaid  with  interest,  and 
what  that  other  world  shall  have  taught  us  will  re- 
dound to  a  better  knowledge  of  our  own,  and  of  that 
cosmos  of  which  the  two  form  part. 


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INDEX 


Adamas, 

unmistakable   double   in    1903, 

214. 
Aeria, 

white  in,  76; 

ruddy  color  of,  148. 
Air  (see  Atmosphere),  86; 

necessity  of,  to  life,  166,  167; 

as   important   to    astronomical 

calculations,  7. 
Air-waves,  250,  251,  273. 
Albedo,  low,  162,  167. 
Algse,  349. 
Amenthes, 

hibernation  of,  317-324. 
Animalcula, 

in  almost  boiling  geysers,  349. 
Aonium  Sinus, 

two  doubles  suspected  in,  242. 
Aquae  Calidae,  208,  253,  315. 
Archaean  age   of   the  earth,   132, 

133,  138. 
Areography,  20-31; 

beginning  and  progress  of,  109; 

three  periods  in,  24. 
Arizona,  16; 

in  desert  belt,  13; 

plateau  of,  18. 
Arnon, 

convergent  double,  240. 
Artificiality, 

of  canal  system,  366,  368,  369, 
370,  374; 

of  oases,  366,  371. 
Ascraeus  Lucus,  331; 

embraced  by  the  double  Gigas, 

257. 
Astaboras, 

connection  with  Lucus  Ismenius, 
260-263. 


Atmosphere,  of  Mars,  62,  63,  71, 

78,  79,  87; 
shown  to  exist,  80,  82,  83,  84, 

163,  167; 

rare,  85,  86,  162,  167; 
effect  on  temperature,  80; 
constituents  of,  162,  164,   166, 

168. 
Autumn,  length  of  Martian, 

in     northern     hemisphere,    35, 

48; 

in  southern,  35,  48. 
Axial  tiltj  34,  36,  55,  155,  161; 
determinations  of,  34,  36,  155; 
determines  character  of  seasons, 

34,  36; 
effect    of,    on    presentation    of 

arctic  and  antarctic  regions, 

70; 
effect    of,    on    temperature    of 

arctic  and  temperate  regions, 

88. 

Bacteria, 

plasm-eating  beings,  353. 
Barometric  pressure,  63,  85. 
Beer,  23,  26,  109. 
Bilateralism,  208; 

inherent    attribute    of    canals, 

209. 
Blue  band, 

surrounding  polar  caps,  39,  40, 
42,  43,  56,  61,  63,  71,  161,  162, 
168,  338,  339. 

Blue-green  areas  (see    Dark    Re- 
gions), 32,  67,  163; 
taken  for  seas,  1 10. 
British  Nautical  Almanac,  35. 
Brontes, 

development  of,  304-312. 


2c 


385 


386 


INDEX 


Cambrian  era  of  Earth,  139. 
Camera,  the,  272 ; 

advantage  of,  273; 

slower  than  the  eye,  273  ; 

stars  the  peculiar  province  of, 

273,  274. 
Canals,  11,  32,  163; 

discovery  of,  24,  26; 

considered  straits,  27; 

regularity  of,  28,  29; 

unnatural  in  look,  173; 

manner  of  introduction  of,  174; 

conditions  necessary  to  seeing 
of,  174-177,  282,  283; 

pencil-like  lines,  177,  179,  367; 

definite  in  direction,  178; 

name,  180; 

width  of,  179,  180,  182; 

length  of,  183; 

visible  by  virtue  of  length,  181 ; 

oddities  of,  183; 

number  of,  184; 

systematic  arrangement  of,  184, 
185,  187-191,  248; 

connect  with  polar  caps,   325, 
339,  373; 

import  of  system  of,  338,  372, 
373; 

intrinsic   change   in,   283,   284, 
337,  338; 

what  they  are  not,  185-187,  373; 

zonal  distribution  of,  188,  189; 

departure-points,  190  ; 

dependent     on   general    topog- 
raphy, 191; 

of  later  origin  than  main  fea- 
tures, 191,  247; 

kinematic    character    of,    281- 
303; 

effect  on,  of  illumination,  284; 

drawings     of,     numerous     and 
consecutive,  286 ; 

coordination  of  data,  288,  289; 

curves    of     visibility    of     (see 
Cartouches),  289,  290; 

geometricism  of,  175,  206,  365, 
367,  368 ; 

polar,  327. 


Canals  in  the  dark  regions,  30,  31, 

243-248; 
of    the    southern    hemisphere, 

245; 
of    the    northern    hemisphere, 

246,  247; 

detection  of,  243,  245; 
deprived  seas  of  marine  charac- 
ter, 243; 
part  of  canal  system,  244,  245, 

247. 

Caps  (see  Polar  Caps) . 
Carbon  dioxide,  39,  161,  164-168. 
Carbonic  era  of  Earth,  134,  141, 

142. 
Carets,  265-270; 

natural  formations,  231,  232; 
form    and     position     of,    266, 

267; 

reason  for  shape  of,  268; 
associated    with    canals,    267, 

269; 

help  in  solution  of  riddle,  270 ; 
act  like  oases,  333. 
Cartouches    of    the    canals,    289- 

303; 
interpretation  of,  291-293,  299- 

303,  344-347; 

arranged  by  latitudes,  294; 
showing  first  frosts,  299; 
minimum  points  of,  297,  344; 
maximum  point  of,  301; 
mean  canal,  297,  298. 
Cenozoic  times,  144. 
Cerberus, 

obliterated   by  white  spot,  75. 
Change,  4,  281. 

shown  in  polar  caps,  37,  338 ; 
in   blue-green  areas,   113,    114, 
115,  120,  122-127,  163,  164; 
in  canals,   168,   169,  205,  283- 

285,  314,  337,  338. 
in  oases,  250-252,  330,  331,  337, 

338. 
Chromacea,  352; 

plasm-forming  beings,  353; 
close  to  inorganic  things,  357; 
in  hot  springs,  357,  358. 


INDEX 


387 


Chryse,  90,  102. 
Climate,  82-89; 

one  of  extremes,  87  ; 
temperature,  theoretic  and  ob- 
served, 87; 

non-glaciation  the  rule,  88. 
Clouds,  55,  71,  73,  89,  163,  165, 

283,  284; 

but  few  exist,  83,  165; 
none  over  blue-green  areas,  92  ; 
of  tawny  dust  color,  106; 
probably  dust  storms,  165; 
prove  existence  of  atmosphere, 

167. 

Cold,  87,  167,  299. 
Coloe  Palus, 

in     connection     with      double 

canals,   257,  258,  263. 
Color,  74,  148 ; 

of  Mare  Erythraeum,  122. 
Confervae, 

in  almost  boiling  geysers,  349, 

358. 
Cretaceous  era  of  the  earth,  136, 

143,  151,  152. 
Crystals, 

conditions  of  formation,  357. 

Dana,  131,  139,  140. 
Dark  Regions,  122-125; 

thought  to  be  seas,  110,  111; 
named  in  accordance,  110,  113  ; 
change  in  aspect  cast  doubt  on 

marine  character  of,  113,  114; 
change  in,  considered  seasonal, 

115,  120,  127,  163,  164; 
marine  character  lost,  30,  115- 

118,  163,  164; 
traversed  by  permanent  lines, 

30,  31,  117,  163,  169; 
vegetation  tracts,  119-127,  163, 

164,  168,  169,  170; 
below  level  of  surrounding  sur- 
face, 130,  164; 
former  ocean  basins,  120,  129, 

131; 
latitudinal  development  in,  123, 

124,  126,  127. 


Dawes,  21,  23,  249,  250,  268. 
Day,  Martian,  length  of,  34,  160, 

166. 
Desert  regions  of  the  earth,   13, 

149-155; 

as  observatory  sites,  12,  13; 
help  explain  Mars,  16,  17,  156; 
color  of,  149,  151; 
compared  with  color  of  Mars, 

150,  163; 

vegetation  in,  150; 
position  of,  153,  154; 
due  to  winds,  154. 
Desertism,  16,  89,  153-158. 
Deserts    (see     Reddish-ochre    re- 
gions) . 

Deuteronilus,  259-261. 
Development  of  canals, 

latitudinal  law  of,  299,  302,  375; 
follows  melting  of  polar  caps, 

302,  338-340; 
across  equator,  373.  375. 
Devonian  era  of  the  earth,  141. 
Diaphragm,  the  great,  265. 
Diplopia,  196. 
Djihoun, 

narrowest  double,  228-230; 
embouchure  of,  219-220; 
connection  with  Luci  Ismenii, 

260,  262. 
Double  Canals, 

first   seen  by   Schiaparelli,   28, 

192; 

impression  of,  193,  204; 
two  classes  of,  224; 
require  steady  definition,  194; 
phenomena  of,    194,   205,   208, 

212,  213; 

physical  bond  between  the  con- 
stituents of,  226; 
connection  with  bays,  232; 
optical  theories  of,  196-203; 
not  illusions,  195-203,  209; 
widths  of,   205,   206,   221-224, 

229,  230,  233; 
length  of,  205; 
seasonal  change  in,  205; 
constituents  of,  204 ; 


388 


INDEX 


Double   Canals,   original   line   of, 

216,  217; 

number  of,  205,  209; 
list  of,  210,  211; 
gemination  period  of,  212,  213; 
direction  of,  234-236; 
zonal  distribution  of,  236-239, 

370; 

distribution  in  longitude,  236; 
tropical  phenomena,  239,  240, 

241,  242; 

compared  with  single  canals,  240 ; 
convergent,  240; 
avoid  blue-green  areas,  241 ; 
connect  with  blue-green  areas, 

242.. 
Dust  storms,  90,  165. 

Earth, 

tilt  of  axis  of ,  34; 

seasons  on,  35; 

polar  caps  of,  38,  41,  44,  45,  51, 
54,  69; 

rainfall  on,  79; 

viewed  from  space,  340; 

vegetal  quickening  opposite  to 

that  on  Mars,  344. 
Eccentricity  of  orbit, 

effect  on  seasons,  46,  48,  52. 
Elevations  on  limb,  96,  97; 

measurement  of,  98. 
Elysium, 

white  in,  75,  76. 
Eocene  era  of  the  earth,  144. 
Eopaleozoic  era,  140. 
Euphrates,  221,  231,  249,  258-261, 
266,  267,  316; 

continuously  double,  213; 

curious  relation  to  the  Portus 
Sigaeus  and  Phison,  218,  219. 
Evolution,  362,  366,  367; 

planetary,  363,  364; 

advance  in,  dependent  on  en- 
vironment, 145,  146. 
Exploration, 

polar,  54. 
Eye, 

relation  to  camera,  272-274. 


Farms  in  Kansas  and  Dakota,  363. 
Fastigium  Aryn,  269; 

origin  of  longitudes,  23,  74. 
Fauna,  361 ; 

of  northern  Arizona,  18; 

linked  with  flora,  349,  350,  358. 
Flagstaff,  Arizona,  16. 
Flammarion,  21,  23,  202. 
Flora,  361; 

linked  with  fauna,  349,  350,  358 ; 

fixtures,  360. 
Focal  length, 

of   objective  in  photographing 

canals,  275. 
Franz  Joseph  Land,  45. 
Frosts, 

first  arctic,  299,  300,  345; 

suggestive  of,  87. 

Galileo,  20,  39. 
Ganges,  270; 

peculiar  development  of,  226- 
228; 

widest  double,  228/229. 
Gemination,  214-221. 

seasonal  phenomenon,  212,  213. 

conditioned     by     convenience, 

218-221. 
Geology, 

shows  the  growing  of  the  land, 

131-138. 
Gigas, 

embracing  the  Ascraeus  Lucus, 

257. 
Gihon, 

embouchure  of,  232. 
Gravitation,  law  of,  160. 
Gravity, 

effect  on  atmosphere,  62; 

force  of,  on  Mars,  63. 
Green,  21,  23,  24. 

Habitability,  159. 
Haeckel,  352,  353,  357. 
Haze, 

at  melting  of  caps,  56,  64-66, 
90,  93,  165; 

recurrent,  94. 


INDEX 


389 


Heat,  46,  47,  50,  146,  155. 
Hellas,  81,90,  91; 

in  winter,  58,  59; 

ruddy  color  of,  148. 
Herschel,  Sir  W.,  34,  37. 
Hibernation   of   canals,    313-324, 

379. 
Hiddckel, 

embouchure  of,  232 ; 

connection  with   Luci  Ismenii, 

260-262. 
Hippalus, 

identical  with  rift,  326,  327. 
Hoarfrost,  78,  79,  81; 

at  equator,  79; 

in  southern  hemisphere,  80,  92. 
Huyghens,  23,  26,  108. 

Ice  sheet, 

effect  of,  52. 
Illumination,  oblique,  97; 

for  measuring  elevations,  98. 
Illusion  theories  of  canals, 

disproved,  293. 
Image  of  sun, 

not   reflected  from  dark  areas, 

112. 

Insolation,  47,  79,  91. 
Intelligence  on  other  worlds, 

method  of  making  itself  known, 

364. 
Islands  south,  91,  244; 

effect   of,   on   isothermal  lines, 
92. 

Jamuna, 

original  line  of,  216,  217. 
Jaxartes, 

polar  canal,  328. 
Jupiter,  33,  372. 
Jurassic  era  of  the  earth,  136,  143, 

144. 
Juturna  Fons, 

a  square  oasis,  263. 

Kaiser,  21,  23,  249. 
Kinetic  theory  of  gases,  83,  146, 
147,  164. 


Kison, 

convergent  double,  240. 

Lacus  Hyperboreus,  246. 
Lampland,  197,  225,  275. 
Lick  Observatory,  100. 
Life, 

necessity  of  air  and  water  to, 
17,  166,  167,  341; 

thin  cold  air  no  bar  to,  18; 

maximum    temperature    deter- 
minative of,  19,  378.  380. 
Life  on  Earth,  349-353; 

dependent  on  conditions,  349- 

355,  357,  379,  380. 
Life  on  Mars,  169,  376; 

vegetal,  348,  359; 

probably    of    high    order,    348, 
359,  377,  378,  381,  382; 

evidence  of,  360-365. 
Limb-light, 

evidence  of  atmosphere,  84,  162, 

167. 

Longitudes,  origin  of,  23,  74. 
Lowell  Observatory, 

Annals,  31,  81; 

Bulletin,  201. 
Lucus  Ismenius,  19,  258; 

only  double  oasis,  259; 

association    with    canals,    260, 

261. 

Lucus  Lunae,  330. 
Lucus  Moeris,  208. 

Maedler,  21,  23,  26,  109. 
Mammal,  349. 


of  Mars,  20-24,  26-29. 
Mare  Acidalium,   115,  242,  246- 
252; 

white  in,  80; 

darker    than    the    Mare    Ery- 

thraeum,  127. 
Mare  Cimmerium,  267. 
Mare  Erythraeum,  113; 

irregular  lines  in,  30; 

in  1903, 122-124; 

in  1905,  124-126. 


390 


INDEX 


Mare  Icarium,  207. 

Mare     Sirenum,     92,     110,     114, 

267. 
Maria, 

on  the  moon,  109,  111; 

not  seas,  112,  113; 

on  Mars,  110; 

not  seas,  117; 

southern  hemisphere,  31. 
Matter,  distribution  of,  355. 
Mercator's  projection,  22,  344. 
Merriam,  18,  19,  379. 
Mesozoic  times  of  the  earth,  135, 

142,  144,  151. 

Meteorology  of  Mars,  63,  93. 
Moisture,  86,  154. 
Monera,  349,  357; 

suggestive  of  crystals,  356. 
Months,  Martian, 

different  from  our  own,  36. 
Mountains, 

not  visible  on  Mars,  100; 

measurement  of,  97-100; 

limit  of  height  visible,  100; 

on  Moon,  98,  99. 

Naarmalcha , 

association  with  Luci  Ismenii, 

260,  261. 
Nageli,  356. 
Nansen,  54. 

Naval   Observatory  at  Washing- 
ton, 16. 
Nectar, 

shows  white,  59. 
Neopaleozoic  times  of  the  Earth, 

140. 

Neptune,  33. 

Nicks  in  the  coastline  (see  Carets) . 
Nilokeras,  double,  209; 

photographed,  225 
Nilosyrtis, 

unlike  other  canals,  262 
Nitio-bacteria,  350,  353. 
Nitrogen,  83,  164,  166,  341 
Nix  Olympica,  74,  78. 
North  America, 

geologic  history  of,  133-137. 


detected  later  than  canals,  30, 

249; 
three  stages  in  appearance  of, 

250-252; 
number  of,  252; 
kinds  of,  252-254,  263; 
shape  of,  253,  371; 
position  of,  254-257,  263; 
connected  with  canals,  256,  257, 

262,  371 ; 

disprove  diplopic  theory,  258; 
objectivity  of,  263  ; 
in  dark  regions,  163,  244,  263, 

264; 
kinematic    character    of,    330- 

333; 
latitudinal   progress  of  change 

in  oases,  331 ; 
evolution  of,  331,  332; 
intrinsic  change  in,  337,  338; 
at  junction  of  canals  only,  255, 

371. 
Observations, 

mutual   corroboration   of,    165, 

166 ; 

among  mountains,  7. 
Organic  Evolution, 

origin  of,  356. 
Orology, 

of  Mars,  62. 
Ovid,  25. 
Oxygen,  83,  164,  166,  167,  341. 

Paleozoic    times    on    the    Earth, 

135. 

Permian  period,  142. 
Personal  equation, 
eliminated,  287. 
Phenological  quickening, 
on  Earth,  342; 
on  Mars,  343. 
Phison,  221,  231,  249,  258,  266, 

267,  316; 

continuously  double,  213; 
connection  with  Euphrates  and 

Portus  Sigaeus,  218,  219. 
Phoenix  Lake,  330. 


INDEX 


391 


Photographs  of   the    canals,    225, 

275-277. 

Photography,  celestial,  271-277. 
Physiographic  conditions, 

on  Mars,  68,  128. 
Pickering,  W.  H.,  330. 
Pierius,  71. 
Polar  caps, 

phenomena  of,  37,  41,  61; 

key  to  comprehension  of  planet, 
37; 

compared  with  those  of  earth, 
41,  46; 

composition  of,  39, 161, 168, 339  ; 

making  of  new,  94; 

position  of,  68; 

aspect  of,  56,  57; 

maxima  and  minima  of,  38, 
41-44,  47-53,  55-57,  66-68, 
162; 

fission  of,  61. 
Polar  seas  (see  Blue  band); 

fresh  water,  162.    . 
Poles,  Martian, 

determination  of,  36. 
Pans  Hedoris,  78. 
Portus  Sigaeus, 

nicks  in  the  coastline,  207,  266, 
267; 

embouchure     to     Phison     and 

Euphrates,  218. 
Precipitation,  51,  79,  154,  155; 

effect  on  glaciation,  52. 
Presentation,  a, 

denned,  287,  288. 
Probability,  law  of,  160. 
Projections  on  the  terminator,  77, 
81,96,  100,  104,  165; 

color  of,  102; 

cause  of,  104-107; 

great  one  of  1903,  101-104; 

of  1900,  104. 
Propontis,  the,  242; 

canals  in,  247 ; 

oases  in,  256. 
Protonilus, 

association  with  Luci  Ismenii, 
260. 


Pseboas     Lucus,    207,    250,    253, 

263; 
anomalous  position  of,  262. 

Quaternary  epoch  of  the  Earth, 
137. 

Reddish-ochre  regions,  153,  155; 

deserts,  149,  156,  163; 

variations  of  tint  in,   32,   148, 

149,  151. 

Rifts,  in  polar  cap,  61-63,  67,  162, 
325-329; 

permanent  in  place,  61,  62; 

not  depressions,  62,  63,  162; 

coincide  with  canals,  326-328; 

explanation  of,  328,  329. 
Rotation, 

early  noted,  108,  109; 

how  determined,  34; 

time  of,  34,  160; 

disclosed  by  markings,   32-34, 
108. 

Snbaeus  Sinus,  23,  207,  268,  269. 
San  Francisco  Peaks,  18,  19,  149, 

379,  380. 
Saturn,  33. 

Scepticism,  27,  28,  204. 
Schaeberle,  30. 

Schiaparelli,  11,  15,  21,  23,  24,  26, 
27,  29,  30,  31,  34,  68,  74,  75, 
81,  114,    115,   120,   121,   173, 
177,  186,  192,  212,  217,  221, 
247,  249,  265,  282,  313,  314, 
325,  337,  367,  .373. 
Seas  (see  Dark  Regions), 
southern,  92; 
formerly  on  Mars  and  the  Moon, 

129; 

internal  absorption  of,  147. 
Seasonal  change, 
metabolic,  169; 
in  canals,  168,  169,  285,  373. 
Seasons, 

like  our  own,  34,  35,  166; 

length  of,  48,  79,  161; 

of  vegetal  growth,  346,  347. 


392 


INDEX 


Secular  change,' 

in  canals,  314. 
Silurian  era  of  the  Earth,  134,  138, 

140. 
Sky, 

blotting  out  of,  14; 

measure  of  extinction  of,  16. 
Sky,  Martian,  89; 

clear,  165. 
Slipher,  101,  103. 
Snow,  345; 

limits  of,  on  Earth  and  Mars, 

108. 

Solis  Lacus,  23,  242. 
Spring,  Martian,  35,  48; 

haze  in,  94. 
S.S.  Challenger, 

concerning  south  polar  cap  of 

earth,  45. 
S.S.  Pagoda,  45. 

Subsidiary  snow  patches,  67,  73. 
Summer,  Martian, 

length  of,  35,  48,  381. 
Surface, 

relatively     flat,     62,     76,     97, 
164; 

covered     by     canal      network, 
243; 

clear-cut  in  good  air,  258; 

in  fluid  equilibrium,  374; 

indicative    of     thin    air,     162, 

167. 
Surface  features, 

reality  of,  proved,  26,  33. 
Syrtis  Major,  22 ; 

first  marking  made  out,  23. 

Tempe, 

white  in,  77,  80. 
Temperature,  78,  147,  165,  166; 

effect  on  life,  358. 
Terminator, 

projections  on,  77,  81,  96,  100- 
107,  114,  165; 

depressions  on,  164. 
Terrane,  108,  265. 
Terraqueousness , 

shown  by  earth,  128,  131. 


Terrestriality, 

follows    terraqueousness,     129, 

131,  137,  144-146; 
earth's    oceans    contracting    in 

size,  131; 

inevitably,  131,  146; 
as  shown  by  Mars  and  the  Moon, 

128,  130,  131; 

as  shown  by  the  geologic  his- 
tory of  earth,  131-137; 
as  shown  by  paleontology,  138- 

144; 
making  a  better  habitat,    145, 

146. 
Tertiary  times  of  the  Earth,  137, 

151. 

Thoth-Nepenthes, 
peculiar  course  of,  208; 
hibernation  of,  315-324. 
Titan,  305. 

Triassic  era,  136,  142,  152. 
Trivium  Charontis, 

canals  and  oases  in,  251,  252, 

256. 

Twilight  arc,  shows  thin  air,  85, 
162. 

Uranus,  33. 

Vegetation,  79,  119-127,  163,  166, 

169,  301; 
color  of  Mare  Erythraeum,  122- 

126; 

proof  of,  170; 
theory    supported    by    rifts    in 

polar  cap,  329; 
most    satisfactory    explanation 

of  phenomena  of  canals,  339, 

341,  344,  345,  347,  348,  373; 
two  seasons  of  growth  of,  346; 
melts  snow,  328. 

Water, 

dearth  of,   128,   161,   163,  166, 

168,  169,  341,  366; 
loss  of,  inevitable,  131; 
speed  of  flow  of,  375; 
from  polar  caps,  340,  374. 


INDEX 


393 


Water-vapor, 

from  polar  caps,  83; 

in  atmosphere,  162,  168. 
Weather,  66,  89,  95. 
Wedge  of  Casius,  242; 

canals  in,  247; 

oases  in,  251,  252,  256. 
Welkin, 

man-manufactured,  13-15. 
White  spots,  32,  165; 

similar  in  look  to  polar  caps, 
73; 

location  and  season  of,  74,  76- 
79,  80,  81; 


White  spots, 

permanency  of,  73,  76; 

indication  of  temperature,  80 

165. 

Winds,  154. 

Winter,  Martian,  35,  48. 
World, 

Mars  another,  4,  5,  169; 

evolution  of  a,  16,  128, 131, 155- 
158,  358. 

Year, 

of  Earth,  35; 
of  Mars,  35,  161. 


A  COMPENDIUM  OF  SPHERICAL  ASTRONOMY 

With  its  applications  to  the  determination  and  reduction  of  positions  of  the  fixed  stars 

By   SIMON    NEWCOMB 

Cloth  8vo  $3.00  net 


PART   I.     PRELIMINARY   SUBJECTS 

CHAPTER  I.    INTRODUCTORY.    NOTES  AND  REFERENCES. 

CHAPTER  II.  DIFFERENCES,  INTERPOLATION,  AND  DEVELOPMENT.  NOTES 
AND  REFERENCES. 

CHAPTER  III.  THE  METHOD  OF  LEAST  SQUARES.  Section  I.  Mean  Values  of 
Quantities.  II.  Determination  of  Probable  Errors.  III.  Equations  of  Condi- 
tion. NOTES  AND  REFERENCES. 

PART   II.     THE   FUNDAMENTAL   PRINCIPLES   OF   SPHERICAL 
ASTRONOMY 

CHAPTER  IV.  SPHERICAL  COORDINATES.  Section  I.  General  Theory.  II.  Prob- 
lems and  Applications  of  the  Theory  of  Spherical  Coordinates. 

CHAPTER  V.  THE  MEASURE  OF  TIME  AND  RELATED  PROBLEMS.  Section  I. 
Solar  and  Sidereal  Time.  II.  The  General  Measure  of  Time.  III.  Problems 
Involving  Time. 

CHAPTER  VI.  PARALLAX  AND  RELATED  SUBJECTS.  Section  I.  Figure  and 
Dimensions  of  the  Earth.  II.  Parallax  and  Semi-diameter. 

CHAFFER  VII.    ABERRATION. 

CHAPTER  VIII.  ASTRONOMICAL  REFRACTION.  Section  I.  The  Atmosphere  as  a 
Refracting  Medium.  II.  Elementary  Exposition  of  Atmospheric  Refraction. 
III.  General  Investigation  of  Astronomical  Refraction.  NOTES  AND  REFER- 
ENCES TO  REFRACTION. 

CHAPTER  IX.  PRECESSION  AND  NUTATION.  Section  I.  Laws  of  the  Precessional 
.  Motion.  II.  Relative  Positions  of  the  Equator  and  Equinox  at  Widely  Sepa- 
rated Epochs.  III.  Nutation.  NOTES  AND  REFERENCES  TO  PRECESSION 
AND  NUTATION. 

PART  III.  REDUCTION  AND  DETERMINATION  OF  POSITIONS  OF  THE 
FIXED  STARS 

CHAPTER  X.  REDUCTION  OF  MEAN  PLACES  OF  THE  FIXED  STARS  FROM  ONE 
EPOCH  TO  ANOTHER.  Section  I.  The  Proper  Motions  of  the  Stars.  II.  Trig- 
onometric Reduction  for  Precession.  III.  Development  of  the  Coordinates  in 
the  Powers  of  the  Time.  NOTES  AND  REFERENCES. 

CHAPTER  XI.  REDUCTION  TO  APPARENT  PLACE.  Section  I.  Reduction  to  Terms 
of  the  First  Order.  II.  Rigorous  Reduction  for  Close  Polar  Stars.  III.  Prac- 
tical Methods  of  Reduction.  IV.  Construction  of  Tables  of  the  Apparent  Places 
of  Fundamental  Stars.  NOTES  AND  REFERENCES. 

CHAPTER  XII.  METHOD  OF  DETERMINING  THE  POSITIONS  OF  STARS  BY  MERID- 
IAN OBSERVATIONS.  Section  I.  Method  of  Determining  Right  Ascensions* 
II.  The  Determination  of  Declinations. 

CHAPTER  XIII.  METHODS  OF  DERIVING  THE  POSITIONS  AND  PROPER  MOTIONS 
OF  THE  STARS  FROM  PUBLISHED  RESULTS  OF  OBSERVATIONS.  Section  I. 
Historical  Review.  II.  Reduction  of  Catalogue  Positions  of  Stars  to  a  Homo- 
geneous System.  III.  Methods  of  Combining  Star  Catalogues. 

NOTES   AND   REFERENCES 

List  of  Independent  Star  Catalogues. 

Catalogues  made  at  Northern  Observatories. 

Catalogues  made  at  Tropical  and  Southern  Observatories. 

APPENDIX 

EXPLANATION  OF  THE  TABLES  OF  THE  APPENDIX.  —  I.  Constants  and  Formuke 
in  Frequent  Use.  II.  Tables  Relating  to  Time  and  Arguments  for  Star  Reduc- 
tions. III.  Centennial  Rates  of  the  Precessional  Motions.  IV.  Tables  and 
Formulae  lor  the  Trigonometric  Reduction  of  Mean  Places  of  Stars.  V.  Reduc- 
tion of  the  Struve-Peters  Precessions  to  the  Adopted  Values.  VI.  Conversion 
of  Longitude  and  Latitude  into  R.  A.  and  Dec.  VII.  Refractions.  VIII.  Co- 
efficients of  Solar  and  Lunar  Nutation.  IX.  Three-place  Logarithms  and 
Trigonometrical  Functions. 

THE    MACMILLAN    COMPANY,   64-66    Fifth  Avenue,  New  York 


